diff --git a/plugins/catalog-backend-module-github/api-report.md b/plugins/catalog-backend-module-github/api-report.md
index ea6bc9e0ea..e749549646 100644
--- a/plugins/catalog-backend-module-github/api-report.md
+++ b/plugins/catalog-backend-module-github/api-report.md
@@ -138,6 +138,8 @@ export class GithubMultiOrgReaderProcessor implements CatalogProcessor {
     logger: Logger;
     orgs: GithubMultiOrgConfig;
     githubCredentialsProvider?: GithubCredentialsProvider;
+    userTransformer?: UserTransformer;
+    teamTransformer?: TeamTransformer;
   });
   // (undocumented)
   static fromConfig(
@@ -145,6 +147,8 @@ export class GithubMultiOrgReaderProcessor implements CatalogProcessor {
     options: {
       logger: Logger;
       githubCredentialsProvider?: GithubCredentialsProvider;
+      userTransformer?: UserTransformer;
+      teamTransformer?: TeamTransformer;
     },
   ): GithubMultiOrgReaderProcessor;
   // (undocumented)
diff --git a/plugins/catalog-backend-module-github/src/lib/org.ts b/plugins/catalog-backend-module-github/src/lib/org.ts
index 4642be0e8c..275c5f4aeb 100644
--- a/plugins/catalog-backend-module-github/src/lib/org.ts
+++ b/plugins/catalog-backend-module-github/src/lib/org.ts
@@ -14,7 +14,11 @@
  * limitations under the License.
  */
 
-import { GroupEntity, UserEntity } from '@backstage/catalog-model';
+import {
+  DEFAULT_NAMESPACE,
+  GroupEntity,
+  UserEntity,
+} from '@backstage/catalog-model';
 
 export function buildOrgHierarchy(groups: GroupEntity[]) {
   const groupsByName = new Map(groups.map(g => [g.metadata.name, g]));
@@ -56,9 +60,11 @@ export function assignGroupsToUsers(
 ) {
   const groupMemberUsers = new Map(
     groups.map(group => {
-      const groupKey = group.metadata.namespace
-        ? `${group.metadata.namespace}/${group.metadata.name}`
-        : group.metadata.name;
+      const groupKey =
+        group.metadata.namespace &&
+        group.metadata.namespace !== DEFAULT_NAMESPACE
+          ? `${group.metadata.namespace}/${group.metadata.name}`
+          : group.metadata.name;
       return [groupKey, group.spec.members || []];
     }),
   );
diff --git a/plugins/catalog-backend-module-github/src/processors/GithubMultiOrgReaderProcessor.ts b/plugins/catalog-backend-module-github/src/processors/GithubMultiOrgReaderProcessor.ts
index 59f9fdeeba..745f52d6c5 100644
--- a/plugins/catalog-backend-module-github/src/processors/GithubMultiOrgReaderProcessor.ts
+++ b/plugins/catalog-backend-module-github/src/processors/GithubMultiOrgReaderProcessor.ts
@@ -40,6 +40,8 @@ import {
   getOrganizationUsers,
   GithubMultiOrgConfig,
   readGithubMultiOrgConfig,
+  TeamTransformer,
+  UserTransformer,
 } from '../lib';
 
 /**
@@ -60,6 +62,8 @@ export class GithubMultiOrgReaderProcessor implements CatalogProcessor {
     options: {
       logger: Logger;
       githubCredentialsProvider?: GithubCredentialsProvider;
+      userTransformer?: UserTransformer;
+      teamTransformer?: TeamTransformer;
     },
   ) {
     const c = config.getOptionalConfig('catalog.processors.githubMultiOrg');
@@ -72,12 +76,16 @@ export class GithubMultiOrgReaderProcessor implements CatalogProcessor {
     });
   }
 
-  constructor(options: {
-    integrations: ScmIntegrationRegistry;
-    logger: Logger;
-    orgs: GithubMultiOrgConfig;
-    githubCredentialsProvider?: GithubCredentialsProvider;
-  }) {
+  constructor(
+    private options: {
+      integrations: ScmIntegrationRegistry;
+      logger: Logger;
+      orgs: GithubMultiOrgConfig;
+      githubCredentialsProvider?: GithubCredentialsProvider;
+      userTransformer?: UserTransformer;
+      teamTransformer?: TeamTransformer;
+    },
+  ) {
     this.integrations = options.integrations;
     this.logger = options.logger;
     this.orgs = options.orgs;
@@ -133,12 +141,15 @@ export class GithubMultiOrgReaderProcessor implements CatalogProcessor {
           client,
           orgConfig.name,
           tokenType,
+          this.options.userTransformer,
         );
         const { groups } = await getOrganizationTeams(
           client,
           orgConfig.name,
           async (team, ctx): Promise<GroupEntity | undefined> => {
-            const result = await defaultOrganizationTeamTransformer(team, ctx);
+            const result = this.options.teamTransformer
+              ? await this.options.teamTransformer(team, ctx)
+              : await defaultOrganizationTeamTransformer(team, ctx);
 
             if (result) {
               result.metadata.namespace = orgConfig.groupNamespace;