diff --git a/src/server/routes/admin-tags.ts b/src/server/routes/admin-tags.ts
new file mode 100644
index 0000000..4683df4
--- /dev/null
+++ b/src/server/routes/admin-tags.ts
@@ -0,0 +1,80 @@
+import { zValidator } from "@hono/zod-validator";
+import { Hono } from "hono";
+import { z } from "zod";
+import { parseId } from "../lib/params.ts";
+import {
+	createTag,
+	deleteTag,
+	getAdminTags,
+	getTagWithCounts,
+	updateTag,
+} from "../services/tag.service.ts";
+
+type Env = { Variables: { db?: any; userId?: number } };
+
+const app = new Hono<Env>();
+
+const createTagSchema = z.object({
+	name: z.string().min(1),
+	parentId: z.number().int().positive().nullable().optional(),
+});
+
+const updateTagSchema = z.object({
+	name: z.string().min(1).optional(),
+	parentId: z.number().int().positive().nullable().optional(),
+});
+
+// GET /api/admin/tags — list all tags with parentId and itemCount
+app.get("/", async (c) => {
+	const db = c.get("db");
+	const result = await getAdminTags(db);
+	return c.json(result);
+});
+
+// GET /api/admin/tags/:id — single tag with counts
+app.get("/:id", async (c) => {
+	const db = c.get("db");
+	const id = parseId(c.req.param("id"));
+	if (!id) return c.json({ error: "Invalid tag ID" }, 400);
+	const tag = await getTagWithCounts(db, id);
+	if (!tag) return c.json({ error: "Tag not found" }, 404);
+	return c.json(tag);
+});
+
+// POST /api/admin/tags — create a new tag
+app.post("/", zValidator("json", createTagSchema), async (c) => {
+	const db = c.get("db");
+	const data = c.req.valid("json");
+	const tag = await createTag(db, data);
+	return c.json(tag, 201);
+});
+
+// PUT /api/admin/tags/:id — rename and/or reparent a tag
+app.put("/:id", zValidator("json", updateTagSchema), async (c) => {
+	const db = c.get("db");
+	const id = parseId(c.req.param("id"));
+	if (!id) return c.json({ error: "Invalid tag ID" }, 400);
+	const data = c.req.valid("json");
+	try {
+		const tag = await updateTag(db, id, data);
+		if (!tag) return c.json({ error: "Tag not found" }, 404);
+		return c.json(tag);
+	} catch (err) {
+		if (err instanceof Error && err.message.startsWith("Cycle detected")) {
+			return c.json({ error: err.message }, 400);
+		}
+		throw err;
+	}
+});
+
+// DELETE /api/admin/tags/:id — remove tag (children become top-level via ON DELETE SET NULL)
+app.delete("/:id", async (c) => {
+	const db = c.get("db");
+	const id = parseId(c.req.param("id"));
+	if (!id) return c.json({ error: "Invalid tag ID" }, 400);
+	const deleted = await deleteTag(db, id);
+	if (!deleted) return c.json({ error: "Tag not found" }, 404);
+	return c.json({ success: true });
+});
+
+export { app as adminTagRoutes };
diff --git a/src/server/routes/admin.ts b/src/server/routes/admin.ts
index ef1986e..21cecfc 100644
--- a/src/server/routes/admin.ts
+++ b/src/server/routes/admin.ts
@@ -1,6 +1,7 @@
 import { Hono } from "hono";
 import { requireAdmin, requireAuth } from "../middleware/auth.ts";
 import { adminItemRoutes } from "./admin-items.ts";
+import { adminTagRoutes } from "./admin-tags.ts";
 
 type Env = { Variables: { db?: any; userId?: number } };
 
@@ -17,4 +18,7 @@ app.get("/", async (c) => {
 // Admin item management
 app.route("/items", adminItemRoutes);
 
+// Admin tag management
+app.route("/tags", adminTagRoutes);
+
 export { app as adminRoutes };
diff --git a/tests/routes/admin-tags.test.ts b/tests/routes/admin-tags.test.ts
new file mode 100644
index 0000000..9869572
--- /dev/null
+++ b/tests/routes/admin-tags.test.ts
@@ -0,0 +1,183 @@
+import { beforeEach, describe, expect, it } from "bun:test";
+import { Hono } from "hono";
+import { tags } from "../../src/db/schema.ts";
+import { adminTagRoutes } from "../../src/server/routes/admin-tags.ts";
+import { createTestDb } from "../helpers/db.ts";
+
+function createTestApp(db: any) {
+	const app = new Hono();
+	app.use("*", async (c, next) => {
+		c.set("db", db);
+		await next();
+	});
+	app.route("/api/admin/tags", adminTagRoutes);
+	return app;
+}
+
+async function insertTag(db: any, name: string, parentId?: number | null) {
+	const [row] = await db
+		.insert(tags)
+		.values({ name, parentId: parentId ?? null })
+		.returning();
+	return row!;
+}
+
+describe("Admin Tag Routes", () => {
+	let app: Hono;
+	let db: Awaited<ReturnType<typeof createTestDb>>["db"];
+
+	beforeEach(async () => {
+		const testDb = await createTestDb();
+		db = testDb.db;
+		app = createTestApp(db);
+	});
+
+	describe("GET /api/admin/tags", () => {
+		it("returns 200 with empty array when no tags", async () => {
+			const res = await app.request("/api/admin/tags");
+			expect(res.status).toBe(200);
+			const body = await res.json();
+			expect(body).toEqual([]);
+		});
+
+		it("returns tags with id, name, parentId, itemCount fields after seeding", async () => {
+			await insertTag(db, "bikepacking");
+			const res = await app.request("/api/admin/tags");
+			expect(res.status).toBe(200);
+			const body = await res.json();
+			expect(body).toHaveLength(1);
+			expect(body[0]).toMatchObject({
+				id: expect.any(Number),
+				name: "bikepacking",
+				parentId: null,
+				itemCount: expect.any(Number),
+			});
+		});
+	});
+
+	describe("POST /api/admin/tags", () => {
+		it("returns 201 with created tag", async () => {
+			const res = await app.request("/api/admin/tags", {
+				method: "POST",
+				headers: { "Content-Type": "application/json" },
+				body: JSON.stringify({ name: "ultralight" }),
+			});
+			expect(res.status).toBe(201);
+			const body = await res.json();
+			expect(body).toMatchObject({ id: expect.any(Number), name: "ultralight", parentId: null });
+		});
+
+		it("creates tag with parentId", async () => {
+			const parent = await insertTag(db, "gear");
+			const res = await app.request("/api/admin/tags", {
+				method: "POST",
+				headers: { "Content-Type": "application/json" },
+				body: JSON.stringify({ name: "clothing", parentId: parent.id }),
+			});
+			expect(res.status).toBe(201);
+			const body = await res.json();
+			expect(body.parentId).toBe(parent.id);
+		});
+
+		it("returns 400 for empty name", async () => {
+			const res = await app.request("/api/admin/tags", {
+				method: "POST",
+				headers: { "Content-Type": "application/json" },
+				body: JSON.stringify({ name: "" }),
+			});
+			expect(res.status).toBe(400);
+		});
+	});
+
+	describe("PUT /api/admin/tags/:id", () => {
+		it("renames a tag", async () => {
+			const tag = await insertTag(db, "old-name");
+			const res = await app.request(`/api/admin/tags/${tag.id}`, {
+				method: "PUT",
+				headers: { "Content-Type": "application/json" },
+				body: JSON.stringify({ name: "new-name" }),
+			});
+			expect(res.status).toBe(200);
+			const body = await res.json();
+			expect(body.name).toBe("new-name");
+		});
+
+		it("updates parentId", async () => {
+			const parent = await insertTag(db, "parent");
+			const child = await insertTag(db, "child");
+			const res = await app.request(`/api/admin/tags/${child.id}`, {
+				method: "PUT",
+				headers: { "Content-Type": "application/json" },
+				body: JSON.stringify({ parentId: parent.id }),
+			});
+			expect(res.status).toBe(200);
+			const body = await res.json();
+			expect(body.parentId).toBe(parent.id);
+		});
+
+		it("sets parentId to null (reparent to top-level)", async () => {
+			const parent = await insertTag(db, "parent");
+			const child = await insertTag(db, "child", parent.id);
+			const res = await app.request(`/api/admin/tags/${child.id}`, {
+				method: "PUT",
+				headers: { "Content-Type": "application/json" },
+				body: JSON.stringify({ parentId: null }),
+			});
+			expect(res.status).toBe(200);
+			const body = await res.json();
+			expect(body.parentId).toBeNull();
+		});
+
+		it("returns 400 for cycle (A->B->C, try to set A as child of C)", async () => {
+			const a = await insertTag(db, "A");
+			const b = await insertTag(db, "B", a.id);
+			const c = await insertTag(db, "C", b.id);
+			const res = await app.request(`/api/admin/tags/${a.id}`, {
+				method: "PUT",
+				headers: { "Content-Type": "application/json" },
+				body: JSON.stringify({ parentId: c.id }),
+			});
+			expect(res.status).toBe(400);
+			const body = await res.json();
+			expect(body.error).toContain("Cycle detected");
+		});
+
+		it("returns 404 for non-existent id", async () => {
+			const res = await app.request("/api/admin/tags/99999", {
+				method: "PUT",
+				headers: { "Content-Type": "application/json" },
+				body: JSON.stringify({ name: "ghost" }),
+			});
+			expect(res.status).toBe(404);
+		});
+	});
+
+	describe("DELETE /api/admin/tags/:id", () => {
+		it("returns 200 with { success: true }", async () => {
+			const tag = await insertTag(db, "to-delete");
+			const res = await app.request(`/api/admin/tags/${tag.id}`, {
+				method: "DELETE",
+			});
+			expect(res.status).toBe(200);
+			const body = await res.json();
+			expect(body).toEqual({ success: true });
+		});
+
+		it("children become orphans (parentId null) after parent deletion", async () => {
+			const parent = await insertTag(db, "parent");
+			const child = await insertTag(db, "child", parent.id);
+			await app.request(`/api/admin/tags/${parent.id}`, { method: "DELETE" });
+			const res = await app.request("/api/admin/tags");
+			const body = await res.json();
+			const childRow = body.find((t: any) => t.id === child.id);
+			expect(childRow?.parentId).toBeNull();
+		});
+
+		it("returns 404 for non-existent id", async () => {
+			const res = await app.request("/api/admin/tags/99999", {
+				method: "DELETE",
+			});
+			expect(res.status).toBe(404);
+		});
+	});
+});