diff --git a/docs/usage/self-hosted-configuration.md b/docs/usage/self-hosted-configuration.md
index 5dcbf4f77d6038..52fbdd607b6c92 100644
--- a/docs/usage/self-hosted-configuration.md
+++ b/docs/usage/self-hosted-configuration.md
@@ -213,6 +213,11 @@ For example:
 }
 ```
 
+<!-- prettier-ignore -->
+!!! note
+    On Gitea/Forgejo, you can't use `autodiscoverTopics` together with `autodiscoverNamespaces` because both platforms do not support this.
+    Topics are preferred and `autodiscoverNamespaces` will be ignored when you configure `autodiscoverTopics` on Gitea/Forgejo.
+
 ## autodiscoverProjects
 
 You can use this option to filter the list of autodiscovered repositories by project names.
diff --git a/lib/config/options/index.ts b/lib/config/options/index.ts
index d5e9c2547cb7a3..d924c13b359e9f 100644
--- a/lib/config/options/index.ts
+++ b/lib/config/options/index.ts
@@ -897,7 +897,7 @@ const options: RenovateOptions[] = [
     subType: 'string',
     default: null,
     globalOnly: true,
-    supportedPlatforms: ['gitlab'],
+    supportedPlatforms: ['gitea', 'gitlab'],
   },
   {
     name: 'autodiscoverProjects',
diff --git a/lib/modules/platform/gitea/gitea-helper.spec.ts b/lib/modules/platform/gitea/gitea-helper.spec.ts
index 28bcf498247421..9ee88efbffe430 100644
--- a/lib/modules/platform/gitea/gitea-helper.spec.ts
+++ b/lib/modules/platform/gitea/gitea-helper.spec.ts
@@ -22,6 +22,7 @@ import {
   getRepoLabels,
   getVersion,
   mergePR,
+  orgListRepos,
   requestPrReviewers,
   searchIssues,
   searchRepos,
@@ -250,6 +251,15 @@ describe('modules/platform/gitea/gitea-helper', () => {
     });
   });
 
+  describe('orgListRepos', () => {
+    it('should call /api/v1/orgs/[organization]/repos endpoint', async () => {
+      httpMock.scope(baseUrl).get('/orgs/some/repos').reply(200, mockRepo);
+
+      const res = await orgListRepos('some');
+      expect(res).toEqual(mockRepo);
+    });
+  });
+
   describe('getRepo', () => {
     it('should call /api/v1/repos/[repo] endpoint', async () => {
       httpMock
diff --git a/lib/modules/platform/gitea/gitea-helper.ts b/lib/modules/platform/gitea/gitea-helper.ts
index 3b25b850efeffc..fffa9dc5d13106 100644
--- a/lib/modules/platform/gitea/gitea-helper.ts
+++ b/lib/modules/platform/gitea/gitea-helper.ts
@@ -75,6 +75,19 @@ export async function searchRepos(
   return res.body.data;
 }
 
+export async function orgListRepos(
+  organization: string,
+  options?: GiteaHttpOptions,
+): Promise<Repo[]> {
+  const url = `${API_PATH}/orgs/${organization}/repos`;
+  const res = await giteaHttp.getJson<Repo[]>(url, {
+    ...options,
+    paginate: true,
+  });
+
+  return res.body;
+}
+
 export async function getRepo(
   repoPath: string,
   options?: GiteaHttpOptions,
diff --git a/lib/modules/platform/gitea/index.spec.ts b/lib/modules/platform/gitea/index.spec.ts
index 2a8de9e8c40bad..30fc9c6fab8de9 100644
--- a/lib/modules/platform/gitea/index.spec.ts
+++ b/lib/modules/platform/gitea/index.spec.ts
@@ -72,6 +72,12 @@ describe('modules/platform/gitea/index', () => {
 
   const mockTopicRepos: Repo[] = [partial<Repo>({ full_name: 'a/b' })];
 
+  const mockNamespaceRepos: Repo[] = [
+    partial<Repo>({ full_name: 'org1/repo' }),
+    partial<Repo>({ full_name: 'org2/repo' }),
+    partial<Repo>({ full_name: 'org2/repo2', archived: true }),
+  ];
+
   const mockPRs: MockPr[] = [
     partial<MockPr>({
       number: 1,
@@ -390,6 +396,20 @@ describe('modules/platform/gitea/index', () => {
       expect(repos).toEqual(['a/b']);
     });
 
+    it('should query the organization endpoint for each namespace', async () => {
+      const scope = httpMock.scope('https://gitea.com/api/v1');
+
+      scope.get('/orgs/org1/repos').reply(200, mockNamespaceRepos);
+      scope.get('/orgs/org2/repos').reply(200, mockNamespaceRepos);
+
+      await initFakePlatform(scope);
+
+      const repos = await gitea.getRepos({
+        namespaces: ['org1', 'org2'],
+      });
+      expect(repos).toEqual(['org1/repo', 'org2/repo']);
+    });
+
     it('Sorts repos', async () => {
       process.env.RENOVATE_X_AUTODISCOVER_REPO_SORT = 'updated';
       process.env.RENOVATE_X_AUTODISCOVER_REPO_ORDER = 'desc';
diff --git a/lib/modules/platform/gitea/index.ts b/lib/modules/platform/gitea/index.ts
index dd03749ca263f5..4482eb1b9db37b 100644
--- a/lib/modules/platform/gitea/index.ts
+++ b/lib/modules/platform/gitea/index.ts
@@ -319,12 +319,28 @@ const platform: Platform = {
   async getRepos(config?: AutodiscoverConfig): Promise<string[]> {
     logger.debug('Auto-discovering Gitea repositories');
     try {
-      if (!config?.topics) {
+      if (config?.topics) {
+        logger.debug({ topics: config.topics }, 'Auto-discovering by topics');
+        const repos = await map(config.topics, fetchRepositories);
+        return deduplicateArray(repos.flat());
+      } else if (config?.namespaces) {
+        logger.debug(
+          { namespaces: config.namespaces },
+          'Auto-discovering by organization',
+        );
+        const repos = await map(
+          config.namespaces,
+          async (organization: string) => {
+            const orgRepos = await helper.orgListRepos(organization);
+            return orgRepos
+              .filter((r) => !r.mirror && !r.archived)
+              .map((r) => r.full_name);
+          },
+        );
+        return deduplicateArray(repos.flat());
+      } else {
         return await fetchRepositories();
       }
-
-      const repos = await map(config.topics, fetchRepositories);
-      return deduplicateArray(repos.flat());
     } catch (err) {
       logger.error({ err }, 'Gitea getRepos() error');
       throw err;