diff --git a/src/Explorer/Controls/GitHub/AddRepoComponent.tsx b/src/Explorer/Controls/GitHub/AddRepoComponent.tsx
index a8d29efe0..07974372d 100644
--- a/src/Explorer/Controls/GitHub/AddRepoComponent.tsx
+++ b/src/Explorer/Controls/GitHub/AddRepoComponent.tsx
@@ -1,14 +1,14 @@
 import { DefaultButton, IButtonProps, ITextFieldProps, TextField } from "@fluentui/react";
 import * as React from "react";
 import * as Constants from "../../../Common/Constants";
+import * as UrlUtility from "../../../Common/UrlUtility";
+import { IGitHubRepo } from "../../../GitHub/GitHubClient";
 import { Action } from "../../../Shared/Telemetry/TelemetryConstants";
+import * as TelemetryProcessor from "../../../Shared/Telemetry/TelemetryProcessor";
+import * as GitHubUtils from "../../../Utils/GitHubUtils";
+import Explorer from "../../Explorer";
 import { RepoListItem } from "./GitHubReposComponent";
 import { ChildrenMargin } from "./GitHubStyleConstants";
-import * as GitHubUtils from "../../../Utils/GitHubUtils";
-import { IGitHubRepo } from "../../../GitHub/GitHubClient";
-import * as TelemetryProcessor from "../../../Shared/Telemetry/TelemetryProcessor";
-import * as UrlUtility from "../../../Common/UrlUtility";
-import Explorer from "../../Explorer";
 
 export interface AddRepoComponentProps {
   container: Explorer;
@@ -27,7 +27,6 @@ export class AddRepoComponent extends React.Component<AddRepoComponentProps, Add
   private static readonly ButtonText = "Add";
   private static readonly TextFieldPlaceholder = "https://github.com/owner/repo/tree/branch";
   private static readonly TextFieldErrorMessage = "Invalid url";
-  private static readonly DefaultBranchName = "master";
 
   constructor(props: AddRepoComponentProps) {
     super(props);
@@ -78,7 +77,7 @@ export class AddRepoComponent extends React.Component<AddRepoComponentProps, Add
     });
     let enteredUrl = this.state.textFieldValue;
     if (enteredUrl.indexOf("/tree/") === -1) {
-      enteredUrl = UrlUtility.createUri(enteredUrl, `tree/${AddRepoComponent.DefaultBranchName}`);
+      enteredUrl = UrlUtility.createUri(enteredUrl, `tree/`);
     }
 
     const repoInfo = GitHubUtils.fromRepoUri(enteredUrl);
@@ -93,11 +92,7 @@ export class AddRepoComponent extends React.Component<AddRepoComponentProps, Add
         const item: RepoListItem = {
           key: GitHubUtils.toRepoFullName(repo.owner, repo.name),
           repo,
-          branches: [
-            {
-              name: repoInfo.branch,
-            },
-          ],
+          branches: repoInfo.branch ? [{ name: repoInfo.branch }] : [],
         };
 
         TelemetryProcessor.traceSuccess(
diff --git a/src/Explorer/Controls/GitHub/ReposListComponent.tsx b/src/Explorer/Controls/GitHub/ReposListComponent.tsx
index cdc9cd9c7..60ff973b2 100644
--- a/src/Explorer/Controls/GitHub/ReposListComponent.tsx
+++ b/src/Explorer/Controls/GitHub/ReposListComponent.tsx
@@ -24,11 +24,11 @@ import { RepoListItem } from "./GitHubReposComponent";
 import {
   BranchesDropdownCheckboxStyles,
   BranchesDropdownOptionContainerStyle,
+  BranchesDropdownStyles,
+  BranchesDropdownWidth,
+  ReposListBranchesColumnWidth,
   ReposListCheckboxStyles,
   ReposListRepoColumnMinWidth,
-  ReposListBranchesColumnWidth,
-  BranchesDropdownWidth,
-  BranchesDropdownStyles,
 } from "./GitHubStyleConstants";
 
 export interface ReposListComponentProps {
@@ -44,6 +44,7 @@ export interface BranchesProps {
   lastPageInfo?: IGitHubPageInfo;
   hasMore: boolean;
   isLoading: boolean;
+  defaultBranchName: string;
   loadMore: () => void;
 }
 
@@ -64,7 +65,7 @@ export class ReposListComponent extends React.Component<ReposListComponentProps>
   private static readonly BranchesColumnName = "Branches";
   private static readonly LoadingText = "Loading...";
   private static readonly LoadMoreText = "Load more";
-  private static readonly DefaultBranchName = "master";
+  private static readonly DefaultBranchNames = "master/main";
   private static readonly FooterIndex = -1;
 
   public render(): JSX.Element {
@@ -155,6 +156,10 @@ export class ReposListComponent extends React.Component<ReposListComponentProps>
     }
 
     const branchesProps = this.props.branchesProps[GitHubUtils.toRepoFullName(item.repo.owner, item.repo.name)];
+    if (item.branches.length === 0 && branchesProps.defaultBranchName) {
+      item.branches = [{ name: branchesProps.defaultBranchName }];
+    }
+
     const options: IDropdownOption[] = branchesProps.branches.map((branch) => ({
       key: branch.name,
       text: branch.name,
@@ -198,7 +203,7 @@ export class ReposListComponent extends React.Component<ReposListComponentProps>
     const dropdownProps: IDropdownProps = {
       styles: BranchesDropdownStyles,
       options: [],
-      placeholder: ReposListComponent.DefaultBranchName,
+      placeholder: ReposListComponent.DefaultBranchNames,
       disabled: true,
     };
 
@@ -272,7 +277,7 @@ export class ReposListComponent extends React.Component<ReposListComponentProps>
       styles: ReposListCheckboxStyles,
       onChange: () => {
         const repoListItem = { ...item };
-        repoListItem.branches = [{ name: ReposListComponent.DefaultBranchName }];
+        repoListItem.branches = [];
         this.props.pinRepo(repoListItem);
       },
     };
diff --git a/src/Explorer/Panes/GitHubReposPanel/GitHubReposPanel.tsx b/src/Explorer/Panes/GitHubReposPanel/GitHubReposPanel.tsx
index dfa8667db..f807eeb19 100644
--- a/src/Explorer/Panes/GitHubReposPanel/GitHubReposPanel.tsx
+++ b/src/Explorer/Panes/GitHubReposPanel/GitHubReposPanel.tsx
@@ -35,6 +35,9 @@ interface IGitHubReposPanelState {
 }
 export class GitHubReposPanel extends React.Component<IGitHubReposPanelProps, IGitHubReposPanelState> {
   private static readonly PageSize = 30;
+  private static readonly MasterBranchName = "master";
+  private static readonly MainBranchName = "main";
+
   private isAddedRepo = false;
   private gitHubClient: GitHubClient;
   private junoClient: JunoClient;
@@ -116,6 +119,8 @@ export class GitHubReposPanel extends React.Component<IGitHubReposPanelProps, IG
         if (response.status !== HttpStatusCodes.OK) {
           throw new Error(`Received HTTP ${response.status} when saving pinned repos`);
         }
+
+        this.props.explorer.notebookManager?.refreshPinnedRepos();
       } catch (error) {
         handleError(error, "GitHubReposPane/submit", "Failed to save pinned repos");
       }
@@ -207,6 +212,14 @@ export class GitHubReposPanel extends React.Component<IGitHubReposPanelProps, IG
       if (response.data) {
         branchesProps.branches = branchesProps.branches.concat(response.data);
         branchesProps.lastPageInfo = response.pageInfo;
+        branchesProps.defaultBranchName = branchesProps.branches[0].name;
+        const defaultbranchName = branchesProps.branches.find(
+          (branch) =>
+            branch.name === GitHubReposPanel.MasterBranchName || branch.name === GitHubReposPanel.MainBranchName
+        )?.name;
+        if (defaultbranchName) {
+          branchesProps.defaultBranchName = defaultbranchName;
+        }
       }
     } catch (error) {
       handleError(error, "GitHubReposPane/loadMoreBranches", "Failed to fetch branches");
@@ -298,6 +311,17 @@ export class GitHubReposPanel extends React.Component<IGitHubReposPanelProps, IG
     const existingRepo = this.pinnedReposProps.repos.find((repo) => repo.key === item.key);
     if (existingRepo) {
       existingRepo.branches = item.branches;
+      this.setState({
+        gitHubReposState: {
+          ...this.state.gitHubReposState,
+          reposListProps: {
+            ...this.state.gitHubReposState.reposListProps,
+            pinnedReposProps: {
+              repos: this.pinnedReposProps.repos,
+            },
+          },
+        },
+      });
     } else {
       this.pinnedReposProps.repos = [...this.pinnedReposProps.repos, item];
     }
@@ -374,6 +398,7 @@ export class GitHubReposPanel extends React.Component<IGitHubReposPanelProps, IG
           lastPageInfo: undefined,
           hasMore: true,
           isLoading: true,
+          defaultBranchName: undefined,
           loadMore: (): Promise<void> => this.loadMoreBranches(item.repo),
         };
         this.loadMoreBranches(item.repo);