diff --git a/app/features/api-public/routes/tournament.$id.teams.$teamId.update-member-ign.ts b/app/features/api-public/routes/tournament.$id.teams.$teamId.update-member-ign.ts
new file mode 100644
index 000000000..99f4610e8
--- /dev/null
+++ b/app/features/api-public/routes/tournament.$id.teams.$teamId.update-member-ign.ts
@@ -0,0 +1,49 @@
+import type { ActionFunctionArgs } from "react-router";
+import { z } from "zod";
+import { action as adminAction } from "~/features/tournament/actions/to.$id.admin.server";
+import { IN_GAME_NAME_REGEXP } from "~/features/user-page/user-page-constants";
+import { parseBody, parseParams } from "~/utils/remix.server";
+import { id } from "~/utils/zod";
+import { wrapActionForApi } from "../api-action-wrapper.server";
+
+const paramsSchema = z.object({
+	id,
+	teamId: id,
+});
+
+const bodySchema = z.object({
+	userId: id,
+	inGameName: z.string().regex(IN_GAME_NAME_REGEXP),
+});
+
+export const action = async (args: ActionFunctionArgs) => {
+	const { id: tournamentId } = parseParams({
+		params: args.params,
+		schema: paramsSchema,
+	});
+	const { userId, inGameName } = await parseBody({
+		request: args.request,
+		schema: bodySchema,
+	});
+
+	const hashIndex = inGameName.lastIndexOf("#");
+	const inGameNameText = inGameName.slice(0, hashIndex);
+	const inGameNameDiscriminator = inGameName.slice(hashIndex + 1);
+
+	const internalRequest = new Request(args.request.url, {
+		method: "POST",
+		headers: { "Content-Type": "application/json" },
+		body: JSON.stringify({
+			_action: "UPDATE_IN_GAME_NAME",
+			memberId: userId,
+			inGameNameText,
+			inGameNameDiscriminator,
+		}),
+	});
+
+	return wrapActionForApi(adminAction, {
+		...args,
+		params: { id: String(tournamentId) },
+		request: internalRequest,
+	});
+};
diff --git a/app/features/api-public/schema.ts b/app/features/api-public/schema.ts
index dc9a47966..623260cf6 100644
--- a/app/features/api-public/schema.ts
+++ b/app/features/api-public/schema.ts
@@ -526,3 +526,11 @@ export interface TournamentStartingBracketsBody {
 export interface TournamentTeamMemberBody {
 	userId: number;
 }
+
+/** POST /api/tournament/{id}/teams/{tournamentTeamId}/update-member-ign */
+
+/** @lintignore */
+export interface TournamentUpdateMemberIgnBody {
+	userId: number;
+	inGameName: string;
+}
diff --git a/app/routes.ts b/app/routes.ts
index bc1f17fd8..955159058 100644
--- a/app/routes.ts
+++ b/app/routes.ts
@@ -323,6 +323,10 @@ export default [
 				"/tournament/:id/teams/:teamId/remove-member",
 				"features/api-public/routes/tournament.$id.teams.$teamId.remove-member.ts",
 			),
+			route(
+				"/tournament/:id/teams/:teamId/update-member-ign",
+				"features/api-public/routes/tournament.$id.teams.$teamId.update-member-ign.ts",
+			),
 		]),
 	]),
 
diff --git a/e2e/api-public.spec.ts b/e2e/api-public.spec.ts
index d837add1b..91435e1af 100644
--- a/e2e/api-public.spec.ts
+++ b/e2e/api-public.spec.ts
@@ -317,6 +317,27 @@ test.describe("Public API - Write endpoints", () => {
 		expect(response.status()).toBe(200);
 	});
 
+	test("updates member IGN via API", async ({ page }) => {
+		await seed(page);
+		await impersonate(page, ADMIN_ID);
+
+		const token = await generateWriteToken(page);
+
+		const response = await page.request.fetch(
+			`/api/tournament/${ITZ_TOURNAMENT_ID}/teams/${ITZ_TEAM_ID}/update-member-ign`,
+			{
+				method: "POST",
+				headers: {
+					Authorization: `Bearer ${token}`,
+					"Content-Type": "application/json",
+				},
+				data: { userId: ADMIN_ID, inGameName: "NewName#9999" },
+			},
+		);
+
+		expect(response.status()).toBe(200);
+	});
+
 	test("returns 400 when user is not the organizer of this tournament", async ({
 		page,
 	}) => {