diff --git a/.changeset/big-jars-repair.md b/.changeset/big-jars-repair.md
new file mode 100644
index 0000000000..63fef2c740
--- /dev/null
+++ b/.changeset/big-jars-repair.md
@@ -0,0 +1,5 @@
+---
+'@backstage/plugin-catalog-backend': patch
+---
+
+GitHub discovery processor adds support for discovering the default GitHub branch
diff --git a/plugins/catalog-backend/src/ingestion/processors/GithubDiscoveryProcessor.test.ts b/plugins/catalog-backend/src/ingestion/processors/GithubDiscoveryProcessor.test.ts
index ca8c702c8f..f8647cb5d2 100644
--- a/plugins/catalog-backend/src/ingestion/processors/GithubDiscoveryProcessor.test.ts
+++ b/plugins/catalog-backend/src/ingestion/processors/GithubDiscoveryProcessor.test.ts
@@ -35,7 +35,8 @@ describe('GithubDiscoveryProcessor', () => {
         org: 'foo',
         host: 'github.com',
         repoSearchPath: /^proj$/,
-        catalogPath: '/blob/master/catalog.yaml',
+        branch: 'master',
+        catalogPath: '/catalog.yaml',
       });
       expect(
         parseUrl('https://github.com/foo/proj*/blob/master/catalog.yaml'),
@@ -43,14 +44,21 @@ describe('GithubDiscoveryProcessor', () => {
         org: 'foo',
         host: 'github.com',
         repoSearchPath: /^proj.*$/,
-        catalogPath: '/blob/master/catalog.yaml',
+        branch: 'master',
+        catalogPath: '/catalog.yaml',
+      });
+      expect(parseUrl('https://github.com/foo')).toEqual({
+        org: 'foo',
+        host: 'github.com',
+        repoSearchPath: /^.*$/,
+        branch: '-',
+        catalogPath: '/catalog-info.yaml',
       });
     });
 
     it('throws on incorrectly formed URLs', () => {
       expect(() => parseUrl('https://github.com')).toThrow();
       expect(() => parseUrl('https://github.com//')).toThrow();
-      expect(() => parseUrl('https://github.com/foo')).toThrow();
       expect(() => parseUrl('https://github.com//foo')).toThrow();
       expect(() => parseUrl('https://github.com/org/teams')).toThrow();
       expect(() => parseUrl('https://github.com/org//teams')).toThrow();
@@ -125,11 +133,17 @@ describe('GithubDiscoveryProcessor', () => {
             name: 'backstage',
             url: 'https://github.com/backstage/backstage',
             isArchived: false,
+            defaultBranchRef: {
+              name: 'master',
+            },
           },
           {
             name: 'demo',
             url: 'https://github.com/backstage/demo',
             isArchived: false,
+            defaultBranchRef: {
+              name: 'main',
+            },
           },
         ],
       });
@@ -168,16 +182,25 @@ describe('GithubDiscoveryProcessor', () => {
             name: 'backstage',
             url: 'https://github.com/backstage/backstage',
             isArchived: false,
+            defaultBranchRef: {
+              name: 'main',
+            },
           },
           {
             name: 'techdocs-cli',
             url: 'https://github.com/backstage/techdocs-cli',
             isArchived: false,
+            defaultBranchRef: {
+              name: 'main',
+            },
           },
           {
             name: 'techdocs-container',
             url: 'https://github.com/backstage/techdocs-container',
             isArchived: false,
+            defaultBranchRef: {
+              name: 'main',
+            },
           },
         ],
       });
@@ -215,21 +238,33 @@ describe('GithubDiscoveryProcessor', () => {
             name: 'abstest',
             url: 'https://github.com/backstage/abctest',
             isArchived: false,
+            defaultBranchRef: {
+              name: 'main',
+            },
           },
           {
             name: 'test',
             url: 'https://github.com/backstage/test',
             isArchived: false,
+            defaultBranchRef: {
+              name: 'main',
+            },
           },
           {
             name: 'test-archived',
             url: 'https://github.com/backstage/test',
             isArchived: true,
+            defaultBranchRef: {
+              name: 'main',
+            },
           },
           {
             name: 'testxyz',
             url: 'https://github.com/backstage/testxyz',
             isArchived: false,
+            defaultBranchRef: {
+              name: 'main',
+            },
           },
         ],
       });
diff --git a/plugins/catalog-backend/src/ingestion/processors/GithubDiscoveryProcessor.ts b/plugins/catalog-backend/src/ingestion/processors/GithubDiscoveryProcessor.ts
index f7069a9f64..567f6536d0 100644
--- a/plugins/catalog-backend/src/ingestion/processors/GithubDiscoveryProcessor.ts
+++ b/plugins/catalog-backend/src/ingestion/processors/GithubDiscoveryProcessor.ts
@@ -28,7 +28,18 @@ import { CatalogProcessor, CatalogProcessorEmit } from './types';
 
 /**
  * Extracts repositories out of a GitHub org.
- */
+ *
+ * The following will create locations for all projects which have a catalog-info.yaml
+ * on the default branch. The first is shorthand for the second.
+ *
+ *    target: "https://github.com/backstage"
+ *    or
+ *    target: https://github.com/backstage/*\/blob/-/catalog-info.yaml
+ *
+ * You may also explicitly specify the source branch:
+ *
+ *    target: https://github.com/backstage/*\/blob/main/catalog-info.yaml
+ **/
 export class GithubDiscoveryProcessor implements CatalogProcessor {
   private readonly integrations: ScmIntegrations;
   private readonly logger: Logger;
@@ -65,7 +76,7 @@ export class GithubDiscoveryProcessor implements CatalogProcessor {
       );
     }
 
-    const { org, repoSearchPath, catalogPath, host } = parseUrl(
+    const { org, repoSearchPath, catalogPath, branch, host } = parseUrl(
       location.target,
     );
 
@@ -97,11 +108,14 @@ export class GithubDiscoveryProcessor implements CatalogProcessor {
     );
 
     for (const repository of matching) {
+      const path = `/blob/${
+        branch === '-' ? repository.defaultBranchRef.name : branch
+      }${catalogPath}`;
       emit(
         results.location(
           {
             type: 'url',
-            target: `${repository.url}${catalogPath}`,
+            target: `${repository.url}${path}`,
           },
           // Not all locations may actually exist, since the user defined them as a wildcard pattern.
           // Thus, we emit them as optional and let the downstream processor find them while not outputting
@@ -123,19 +137,31 @@ export function parseUrl(urlString: string): {
   org: string;
   repoSearchPath: RegExp;
   catalogPath: string;
+  branch: string;
   host: string;
 } {
   const url = new URL(urlString);
   const path = url.pathname.substr(1).split('/');
 
   // /backstage/techdocs-*/blob/master/catalog-info.yaml
+  // can also be
+  // /backstage
   if (path.length > 2 && path[0].length && path[1].length) {
     return {
       org: decodeURIComponent(path[0]),
       repoSearchPath: escapeRegExp(decodeURIComponent(path[1])),
-      catalogPath: `/${decodeURIComponent(path.slice(2).join('/'))}`,
+      branch: decodeURIComponent(path[3]),
+      catalogPath: `/${decodeURIComponent(path.slice(4).join('/'))}`,
       host: url.host,
     };
+  } else if (path.length === 1 && path[0].length) {
+    return {
+      org: decodeURIComponent(path[0]),
+      host: url.host,
+      repoSearchPath: escapeRegExp('*'),
+      catalogPath: '/catalog-info.yaml',
+      branch: '-',
+    };
   }
 
   throw new Error(`Failed to parse ${urlString}`);
diff --git a/plugins/catalog-backend/src/ingestion/processors/github/github.test.ts b/plugins/catalog-backend/src/ingestion/processors/github/github.test.ts
index 11cdf671c3..e481355fb4 100644
--- a/plugins/catalog-backend/src/ingestion/processors/github/github.test.ts
+++ b/plugins/catalog-backend/src/ingestion/processors/github/github.test.ts
@@ -201,11 +201,17 @@ describe('github', () => {
                 name: 'backstage',
                 url: 'https://github.com/backstage/backstage',
                 isArchived: false,
+                defaultBranchRef: {
+                  name: 'main',
+                },
               },
               {
                 name: 'demo',
                 url: 'https://github.com/backstage/demo',
                 isArchived: true,
+                defaultBranchRef: {
+                  name: 'main',
+                },
               },
             ],
             pageInfo: {
@@ -221,11 +227,17 @@ describe('github', () => {
             name: 'backstage',
             url: 'https://github.com/backstage/backstage',
             isArchived: false,
+            defaultBranchRef: {
+              name: 'main',
+            },
           },
           {
             name: 'demo',
             url: 'https://github.com/backstage/demo',
             isArchived: true,
+            defaultBranchRef: {
+              name: 'main',
+            },
           },
         ],
       };
diff --git a/plugins/catalog-backend/src/ingestion/processors/github/github.ts b/plugins/catalog-backend/src/ingestion/processors/github/github.ts
index 70479110c2..9eb5073710 100644
--- a/plugins/catalog-backend/src/ingestion/processors/github/github.ts
+++ b/plugins/catalog-backend/src/ingestion/processors/github/github.ts
@@ -60,6 +60,9 @@ export type Repository = {
   name: string;
   url: string;
   isArchived: boolean;
+  defaultBranchRef: {
+    name: string;
+  };
 };
 
 export type Connection<T> = {
@@ -252,6 +255,9 @@ export async function getOrganizationRepositories(
             name
             url
             isArchived
+            defaultBranchRef {
+              name
+            }
           }
           pageInfo {
             hasNextPage