diff --git a/app/models/tournament.ts b/app/models/tournament.ts
index e26659c..2bf7c51 100644
--- a/app/models/tournament.ts
+++ b/app/models/tournament.ts
@@ -1,4 +1,4 @@
-import { eq, and, asc } from "drizzle-orm";
+import { eq, and, asc, desc } from "drizzle-orm";
 import { database } from "~/database/context";
 import * as schema from "~/database/schema";
 
@@ -80,6 +80,50 @@ export async function upsertTournament(
   return await createTournament(data);
 }
 
+export async function findAllTournamentsGroupedBySport(): Promise<
+  Array<{
+    sport: { id: string; name: string };
+    tournaments: Tournament[];
+  }>
+> {
+  const db = database();
+
+  const rows = await db
+    .select({
+      tournament: schema.tournaments,
+      sport: {
+        id: schema.sports.id,
+        name: schema.sports.name,
+      },
+    })
+    .from(schema.tournaments)
+    .innerJoin(schema.sports, eq(schema.tournaments.sportId, schema.sports.id))
+    .orderBy(
+      asc(schema.sports.name),
+      desc(schema.tournaments.year),
+      asc(schema.tournaments.startsAt)
+    );
+
+  const groupMap = new Map<
+    string,
+    { sport: { id: string; name: string }; tournaments: Tournament[] }
+  >();
+
+  for (const row of rows) {
+    const existing = groupMap.get(row.sport.id);
+    if (existing) {
+      existing.tournaments.push(row.tournament);
+    } else {
+      groupMap.set(row.sport.id, {
+        sport: row.sport,
+        tournaments: [row.tournament],
+      });
+    }
+  }
+
+  return Array.from(groupMap.values());
+}
+
 export async function updateTournamentStatus(
   id: string,
   status: TournamentStatus
diff --git a/app/routes.ts b/app/routes.ts
index 9b784d6..9ba6e9b 100644
--- a/app/routes.ts
+++ b/app/routes.ts
@@ -129,6 +129,8 @@ export default [
       "routes/admin.sports-seasons.$id.clone.tsx"
     ),
     route("participants", "routes/admin.participants.tsx"),
+    route("tournaments", "routes/admin.tournaments._index.tsx"),
+    route("tournaments/:id", "routes/admin.tournaments.$id.tsx"),
     route("templates", "routes/admin.templates.tsx"),
     route("templates/new", "routes/admin.templates.new.tsx"),
     route("templates/:id", "routes/admin.templates.$id.tsx"),
diff --git a/app/routes/__tests__/admin.tournaments.$id.test.tsx b/app/routes/__tests__/admin.tournaments.$id.test.tsx
new file mode 100644
index 0000000..1c9059f
--- /dev/null
+++ b/app/routes/__tests__/admin.tournaments.$id.test.tsx
@@ -0,0 +1,182 @@
+import { describe, it, expect, vi, beforeEach } from "vitest";
+
+vi.mock("~/lib/auth.server", () => ({
+  auth: { api: { getSession: vi.fn() } },
+}));
+vi.mock("~/models/user", () => ({
+  isUserAdmin: vi.fn(),
+}));
+vi.mock("~/models/tournament", () => ({
+  getTournamentById: vi.fn(),
+  updateTournamentStatus: vi.fn(),
+}));
+vi.mock("~/models/tournament-result", () => ({
+  getTournamentResults: vi.fn(),
+  upsertTournamentResult: vi.fn(),
+}));
+vi.mock("~/models/participant", () => ({
+  findCanonicalParticipantsBySport: vi.fn(),
+}));
+vi.mock("~/services/sync-tournament-results", () => ({
+  syncTournamentResults: vi.fn(),
+}));
+vi.mock("~/lib/logger", () => ({
+  logger: { error: vi.fn(), info: vi.fn(), warn: vi.fn() },
+}));
+
+import { action } from "~/routes/admin.tournaments.$id";
+import { auth } from "~/lib/auth.server";
+import { isUserAdmin } from "~/models/user";
+import {
+  getTournamentById,
+  updateTournamentStatus,
+} from "~/models/tournament";
+import { upsertTournamentResult } from "~/models/tournament-result";
+import { syncTournamentResults } from "~/services/sync-tournament-results";
+
+const TOURNAMENT_ID = "tournament-1";
+const ADMIN_USER_ID = "admin-1";
+const NON_ADMIN_USER_ID = "user-1";
+
+function makeRequest(body: Record<string, string>) {
+  const formData = new FormData();
+  for (const [k, v] of Object.entries(body)) {
+    formData.append(k, v);
+  }
+  return new Request(`http://localhost/admin/tournaments/${TOURNAMENT_ID}`, {
+    method: "POST",
+    body: formData,
+  });
+}
+
+function makeActionArgs(request: Request) {
+  return {
+    request,
+    params: { id: TOURNAMENT_ID },
+    context: {} as never,
+  } as unknown as Parameters<typeof action>[0];
+}
+
+describe("admin.tournaments.$id action", () => {
+  beforeEach(() => {
+    vi.clearAllMocks();
+  });
+
+  it("batch-upsert-results: upserts each row, marks tournament completed, and fans out", async () => {
+    vi.mocked(auth.api.getSession).mockResolvedValue({
+      user: { id: ADMIN_USER_ID },
+    } as never);
+    vi.mocked(isUserAdmin).mockResolvedValue(true);
+    vi.mocked(getTournamentById).mockResolvedValue({
+      id: TOURNAMENT_ID,
+      sportId: "sport-1",
+      name: "US Open",
+      year: 2026,
+      status: "scheduled",
+    } as never);
+    vi.mocked(upsertTournamentResult).mockResolvedValue({} as never);
+    vi.mocked(updateTournamentStatus).mockResolvedValue({} as never);
+    const syncReport = {
+      tournamentId: TOURNAMENT_ID,
+      windowsSynced: 2,
+      windowsFailed: 0,
+      failures: [],
+    };
+    vi.mocked(syncTournamentResults).mockResolvedValue(syncReport);
+
+    const results = [
+      { participantId: "p-1", placement: 1 },
+      { participantId: "p-2", placement: 2 },
+      { participantId: "p-3", placement: 3 },
+    ];
+    const request = makeRequest({
+      intent: "batch-upsert-results",
+      results: JSON.stringify(results),
+    });
+
+    const response = await action(makeActionArgs(request));
+
+    expect(upsertTournamentResult).toHaveBeenCalledTimes(3);
+    expect(upsertTournamentResult).toHaveBeenCalledWith({
+      tournamentId: TOURNAMENT_ID,
+      participantId: "p-1",
+      placement: 1,
+    });
+    expect(updateTournamentStatus).toHaveBeenCalledWith(
+      TOURNAMENT_ID,
+      "completed"
+    );
+    expect(syncTournamentResults).toHaveBeenCalledWith(TOURNAMENT_ID);
+    expect(response).toMatchObject({
+      success: true,
+      syncReport,
+    });
+  });
+
+  it("does not re-update status when tournament is already completed", async () => {
+    vi.mocked(auth.api.getSession).mockResolvedValue({
+      user: { id: ADMIN_USER_ID },
+    } as never);
+    vi.mocked(isUserAdmin).mockResolvedValue(true);
+    vi.mocked(getTournamentById).mockResolvedValue({
+      id: TOURNAMENT_ID,
+      sportId: "sport-1",
+      name: "US Open",
+      year: 2026,
+      status: "completed",
+    } as never);
+    vi.mocked(upsertTournamentResult).mockResolvedValue({} as never);
+    vi.mocked(syncTournamentResults).mockResolvedValue({
+      tournamentId: TOURNAMENT_ID,
+      windowsSynced: 1,
+      windowsFailed: 0,
+      failures: [],
+    });
+
+    const request = makeRequest({
+      intent: "batch-upsert-results",
+      results: JSON.stringify([{ participantId: "p-1", placement: 1 }]),
+    });
+
+    await action(makeActionArgs(request));
+
+    expect(updateTournamentStatus).not.toHaveBeenCalled();
+    expect(syncTournamentResults).toHaveBeenCalledWith(TOURNAMENT_ID);
+  });
+
+  it("non-admin user is forbidden (403)", async () => {
+    vi.mocked(auth.api.getSession).mockResolvedValue({
+      user: { id: NON_ADMIN_USER_ID },
+    } as never);
+    vi.mocked(isUserAdmin).mockResolvedValue(false);
+
+    const request = makeRequest({
+      intent: "batch-upsert-results",
+      results: JSON.stringify([{ participantId: "p-1", placement: 1 }]),
+    });
+
+    await expect(action(makeActionArgs(request))).rejects.toMatchObject({
+      status: 403,
+    });
+
+    expect(upsertTournamentResult).not.toHaveBeenCalled();
+    expect(syncTournamentResults).not.toHaveBeenCalled();
+  });
+
+  it("missing tournament returns 404", async () => {
+    vi.mocked(auth.api.getSession).mockResolvedValue({
+      user: { id: ADMIN_USER_ID },
+    } as never);
+    vi.mocked(isUserAdmin).mockResolvedValue(true);
+    vi.mocked(getTournamentById).mockResolvedValue(null);
+
+    const request = makeRequest({
+      intent: "batch-upsert-results",
+      results: JSON.stringify([{ participantId: "p-1", placement: 1 }]),
+    });
+
+    await expect(action(makeActionArgs(request))).rejects.toMatchObject({
+      status: 404,
+    });
+  });
+});
diff --git a/app/routes/admin.tournaments.$id.tsx b/app/routes/admin.tournaments.$id.tsx
new file mode 100644
index 0000000..d91e49b
--- /dev/null
+++ b/app/routes/admin.tournaments.$id.tsx
@@ -0,0 +1,353 @@
+import { Link, useFetcher } from "react-router";
+import { auth } from "~/lib/auth.server";
+import type { Route } from "./+types/admin.tournaments.$id";
+
+import { logger } from "~/lib/logger";
+import {
+  getTournamentById,
+  updateTournamentStatus,
+} from "~/models/tournament";
+import {
+  getTournamentResults,
+  upsertTournamentResult,
+} from "~/models/tournament-result";
+import { findCanonicalParticipantsBySport } from "~/models/participant";
+import { isUserAdmin } from "~/models/user";
+import {
+  syncTournamentResults,
+  type SyncReport,
+} from "~/services/sync-tournament-results";
+import {
+  Card,
+  CardContent,
+  CardDescription,
+  CardHeader,
+  CardTitle,
+} from "~/components/ui/card";
+import { Badge } from "~/components/ui/badge";
+import { Button } from "~/components/ui/button";
+import {
+  Table,
+  TableBody,
+  TableCell,
+  TableHead,
+  TableHeader,
+  TableRow,
+} from "~/components/ui/table";
+import { ArrowLeft, CheckCircle2, AlertTriangle } from "lucide-react";
+import { BatchResultEntry } from "~/components/BatchResultEntry";
+
+export function meta({ data }: Route.MetaArgs): Route.MetaDescriptors {
+  return [
+    {
+      title: `${data?.tournament?.name ?? "Tournament"} - Brackt Admin`,
+    },
+  ];
+}
+
+export async function loader({ params }: Route.LoaderArgs) {
+  const tournament = await getTournamentById(params.id);
+  if (!tournament) {
+    throw new Response("Not Found", { status: 404 });
+  }
+
+  const [results, canonicalParticipants] = await Promise.all([
+    getTournamentResults(tournament.id),
+    findCanonicalParticipantsBySport(tournament.sportId),
+  ]);
+
+  return { tournament, results, canonicalParticipants };
+}
+
+export async function action(args: Route.ActionArgs) {
+  const { request, params } = args;
+  const session = await auth.api.getSession({ headers: request.headers });
+  const userId = session?.user.id ?? null;
+  const isAdmin = userId ? await isUserAdmin(userId) : false;
+  if (!isAdmin) {
+    throw new Response("Forbidden", { status: 403 });
+  }
+
+  const tournament = await getTournamentById(params.id);
+  if (!tournament) {
+    throw new Response("Not Found", { status: 404 });
+  }
+
+  const formData = await request.formData();
+  const intent = formData.get("intent");
+
+  if (intent === "batch-upsert-results") {
+    const resultsRaw = formData.get("results");
+    if (typeof resultsRaw !== "string" || !resultsRaw) {
+      return {
+        success: false as const,
+        error: "Missing results payload",
+        syncReport: null,
+      };
+    }
+
+    let parsed: Array<{ participantId: string; placement: number }>;
+    try {
+      parsed = JSON.parse(resultsRaw);
+    } catch {
+      return {
+        success: false as const,
+        error: "Invalid JSON in results payload",
+        syncReport: null,
+      };
+    }
+
+    if (!Array.isArray(parsed)) {
+      return {
+        success: false as const,
+        error: "Results payload must be an array",
+        syncReport: null,
+      };
+    }
+
+    try {
+      for (const row of parsed) {
+        if (
+          !row ||
+          typeof row.participantId !== "string" ||
+          typeof row.placement !== "number"
+        ) {
+          return {
+            success: false as const,
+            error: "Each result must have participantId and placement",
+            syncReport: null,
+          };
+        }
+        await upsertTournamentResult({
+          tournamentId: tournament.id,
+          participantId: row.participantId,
+          placement: row.placement,
+        });
+      }
+
+      if (tournament.status !== "completed") {
+        await updateTournamentStatus(tournament.id, "completed");
+      }
+
+      const syncReport = await syncTournamentResults(tournament.id);
+      return {
+        success: true as const,
+        error: null,
+        syncReport,
+      };
+    } catch (error) {
+      logger.error("batch-upsert-results failed:", error);
+      return {
+        success: false as const,
+        error:
+          error instanceof Error ? error.message : "Failed to save results",
+        syncReport: null,
+      };
+    }
+  }
+
+  if (intent === "retry-window-sync") {
+    try {
+      const syncReport = await syncTournamentResults(tournament.id);
+      return { success: true as const, error: null, syncReport };
+    } catch (error) {
+      logger.error("retry-window-sync failed:", error);
+      return {
+        success: false as const,
+        error:
+          error instanceof Error ? error.message : "Failed to retry sync",
+        syncReport: null,
+      };
+    }
+  }
+
+  return {
+    success: false as const,
+    error: "Invalid intent",
+    syncReport: null,
+  };
+}
+
+export default function AdminTournamentDetail({
+  loaderData,
+  actionData,
+}: Route.ComponentProps) {
+  const { tournament, results, canonicalParticipants } = loaderData;
+  const retryFetcher = useFetcher<typeof action>();
+
+  // Prefer the latest action/retry response for the sync report
+  const liveReport: SyncReport | null =
+    (retryFetcher.data?.syncReport ?? actionData?.syncReport) ?? null;
+
+  const participantById = new Map(
+    canonicalParticipants.map((p) => [p.id, p])
+  );
+
+  return (
+    <div className="p-8">
+      <div className="max-w-5xl">
+        <div className="mb-6">
+          <Button variant="ghost" size="sm" asChild className="mb-2">
+            <Link to="/admin/tournaments">
+              <ArrowLeft className="mr-2 h-4 w-4" />
+              Back to tournaments
+            </Link>
+          </Button>
+          <div className="flex items-center gap-3">
+            <h1 className="text-3xl font-bold">{tournament.name}</h1>
+            <Badge
+              variant={
+                tournament.status === "completed"
+                  ? "default"
+                  : tournament.status === "in_progress"
+                  ? "secondary"
+                  : "outline"
+              }
+            >
+              {tournament.status}
+            </Badge>
+          </div>
+          <p className="text-muted-foreground mt-1">
+            {tournament.year}
+            {tournament.location ? ` — ${tournament.location}` : ""}
+            {tournament.surface ? ` — ${tournament.surface}` : ""}
+          </p>
+        </div>
+
+        {liveReport && (
+          <Card className="mb-6 border-emerald-500/30">
+            <CardHeader>
+              <CardTitle className="flex items-center gap-2 text-emerald-500">
+                <CheckCircle2 className="h-5 w-5" />
+                Synced to {liveReport.windowsSynced}{" "}
+                {liveReport.windowsSynced === 1 ? "window" : "windows"}
+              </CardTitle>
+              <CardDescription>
+                Canonical results were fanned out to every linked scoring
+                window.
+              </CardDescription>
+            </CardHeader>
+            {liveReport.failures.length > 0 && (
+              <CardContent>
+                <div className="rounded-md border border-destructive/50 bg-destructive/10 p-4 space-y-3">
+                  <div className="flex items-center gap-2 text-destructive font-medium">
+                    <AlertTriangle className="h-4 w-4" />
+                    {liveReport.failures.length}{" "}
+                    {liveReport.failures.length === 1 ? "window" : "windows"}{" "}
+                    failed to sync
+                  </div>
+                  <div className="space-y-2">
+                    {liveReport.failures.map((f) => (
+                      <div
+                        key={f.scoringEventId}
+                        className="flex items-start justify-between gap-4 text-sm"
+                      >
+                        <div className="space-y-1">
+                          <div className="font-mono text-xs text-muted-foreground">
+                            event: {f.scoringEventId}
+                          </div>
+                          <div className="font-mono text-xs text-muted-foreground">
+                            season: {f.sportsSeasonId}
+                          </div>
+                          <div className="text-destructive">{f.error}</div>
+                        </div>
+                        <retryFetcher.Form method="post">
+                          <input
+                            type="hidden"
+                            name="intent"
+                            value="retry-window-sync"
+                          />
+                          <input
+                            type="hidden"
+                            name="scoringEventId"
+                            value={f.scoringEventId}
+                          />
+                          <Button
+                            type="submit"
+                            size="sm"
+                            variant="outline"
+                            disabled={retryFetcher.state !== "idle"}
+                          >
+                            {retryFetcher.state !== "idle"
+                              ? "Retrying…"
+                              : "Retry"}
+                          </Button>
+                        </retryFetcher.Form>
+                      </div>
+                    ))}
+                  </div>
+                </div>
+              </CardContent>
+            )}
+          </Card>
+        )}
+
+        {actionData?.error && (
+          <div className="bg-destructive/15 text-destructive px-4 py-3 rounded-md text-sm mb-6">
+            {actionData.error}
+          </div>
+        )}
+
+        <div className="grid gap-6 md:grid-cols-2">
+          <Card>
+            <CardHeader>
+              <CardTitle>Current Results</CardTitle>
+              <CardDescription>
+                {results.length}{" "}
+                {results.length === 1 ? "result" : "results"} recorded
+              </CardDescription>
+            </CardHeader>
+            <CardContent>
+              {results.length === 0 ? (
+                <p className="text-sm text-muted-foreground py-6 text-center">
+                  No results recorded yet. Paste a ranked list to the right to
+                  import.
+                </p>
+              ) : (
+                <Table>
+                  <TableHeader>
+                    <TableRow>
+                      <TableHead className="w-24">Placement</TableHead>
+                      <TableHead>Participant</TableHead>
+                    </TableRow>
+                  </TableHeader>
+                  <TableBody>
+                    {results.map((r) => {
+                      const p = participantById.get(r.participantId);
+                      return (
+                        <TableRow key={r.id}>
+                          <TableCell className="font-semibold">
+                            {r.placement ?? "—"}
+                          </TableCell>
+                          <TableCell>
+                            {p?.name ?? (
+                              <span className="text-muted-foreground font-mono text-xs">
+                                {r.participantId}
+                              </span>
+                            )}
+                          </TableCell>
+                        </TableRow>
+                      );
+                    })}
+                  </TableBody>
+                </Table>
+              )}
+            </CardContent>
+          </Card>
+
+          <BatchResultEntry
+            participants={canonicalParticipants.map((p) => ({
+              id: p.id,
+              name: p.name,
+            }))}
+            sportsSeasonId=""
+            existingResultParticipantIds={
+              new Set(results.map((r) => r.participantId))
+            }
+            intent="batch-upsert-results"
+          />
+        </div>
+      </div>
+    </div>
+  );
+}
diff --git a/app/routes/admin.tournaments._index.tsx b/app/routes/admin.tournaments._index.tsx
new file mode 100644
index 0000000..5753b05
--- /dev/null
+++ b/app/routes/admin.tournaments._index.tsx
@@ -0,0 +1,138 @@
+import { Link } from "react-router";
+import type { Route } from "./+types/admin.tournaments._index";
+
+import { findAllTournamentsGroupedBySport } from "~/models/tournament";
+import {
+  Card,
+  CardContent,
+  CardDescription,
+  CardHeader,
+  CardTitle,
+} from "~/components/ui/card";
+import {
+  Table,
+  TableBody,
+  TableCell,
+  TableHead,
+  TableHeader,
+  TableRow,
+} from "~/components/ui/table";
+import { Badge } from "~/components/ui/badge";
+import { Button } from "~/components/ui/button";
+import { Trophy } from "lucide-react";
+
+export function meta(): Route.MetaDescriptors {
+  return [{ title: "Tournaments - Brackt Admin" }];
+}
+
+export async function loader() {
+  const grouped = await findAllTournamentsGroupedBySport();
+  return { grouped };
+}
+
+export default function AdminTournamentsIndex({
+  loaderData,
+}: Route.ComponentProps) {
+  const { grouped } = loaderData;
+
+  const totalCount = grouped.reduce(
+    (acc, g) => acc + g.tournaments.length,
+    0
+  );
+
+  return (
+    <div className="p-8">
+      <div className="flex items-center justify-between mb-6">
+        <div>
+          <h1 className="text-3xl font-bold">Tournaments</h1>
+          <p className="text-muted-foreground mt-1">
+            Canonical tournaments across all sports. Enter results once here
+            and they fan out to every linked scoring window.
+          </p>
+        </div>
+      </div>
+
+      {grouped.length === 0 ? (
+        <Card>
+          <CardContent className="py-12 text-center">
+            <Trophy className="mx-auto h-12 w-12 text-muted-foreground" />
+            <h3 className="mt-4 text-lg font-semibold">
+              No tournaments yet
+            </h3>
+            <p className="text-muted-foreground mt-2">
+              Canonical tournaments are created automatically by the backfill
+              or data-sync flows.
+            </p>
+          </CardContent>
+        </Card>
+      ) : (
+        <div className="space-y-6">
+          <p className="text-sm text-muted-foreground">
+            {totalCount} {totalCount === 1 ? "tournament" : "tournaments"}{" "}
+            across {grouped.length}{" "}
+            {grouped.length === 1 ? "sport" : "sports"}
+          </p>
+          {grouped.map((group) => (
+            <Card key={group.sport.id}>
+              <CardHeader>
+                <CardTitle>{group.sport.name}</CardTitle>
+                <CardDescription>
+                  {group.tournaments.length}{" "}
+                  {group.tournaments.length === 1
+                    ? "tournament"
+                    : "tournaments"}
+                </CardDescription>
+              </CardHeader>
+              <CardContent>
+                <Table>
+                  <TableHeader>
+                    <TableRow>
+                      <TableHead>Name</TableHead>
+                      <TableHead>Year</TableHead>
+                      <TableHead>Starts</TableHead>
+                      <TableHead>Status</TableHead>
+                      <TableHead className="text-right">Actions</TableHead>
+                    </TableRow>
+                  </TableHeader>
+                  <TableBody>
+                    {group.tournaments.map((t) => (
+                      <TableRow key={t.id}>
+                        <TableCell className="font-medium">{t.name}</TableCell>
+                        <TableCell>{t.year}</TableCell>
+                        <TableCell className="text-muted-foreground">
+                          {t.startsAt
+                            ? new Date(t.startsAt).toLocaleDateString()
+                            : "—"}
+                        </TableCell>
+                        <TableCell>
+                          <Badge
+                            variant={
+                              t.status === "completed"
+                                ? "default"
+                                : t.status === "in_progress"
+                                ? "secondary"
+                                : "outline"
+                            }
+                          >
+                            {t.status}
+                          </Badge>
+                        </TableCell>
+                        <TableCell className="text-right">
+                          <Button variant="ghost" size="sm" asChild>
+                            <Link to={`/admin/tournaments/${t.id}`}>
+                              Open
+                            </Link>
+                          </Button>
+                        </TableCell>
+                      </TableRow>
+                    ))}
+                  </TableBody>
+                </Table>
+              </CardContent>
+            </Card>
+          ))}
+        </div>
+      )}
+    </div>
+  );
+}