diff --git a/api/queries_repo.go b/api/queries_repo.go
index 85d8e0386..702cf7075 100644
--- a/api/queries_repo.go
+++ b/api/queries_repo.go
@@ -504,7 +504,7 @@ type repositoryV3 struct {
 }
 
 // ForkRepo forks the repository on GitHub and returns the new repository
-func ForkRepo(client *Client, repo ghrepo.Interface, org, newName string) (*Repository, error) {
+func ForkRepo(client *Client, repo ghrepo.Interface, org, newName string, defaultBranchOnly bool) (*Repository, error) {
 	path := fmt.Sprintf("repos/%s/forks", ghrepo.FullName(repo))
 
 	params := map[string]interface{}{}
@@ -514,6 +514,9 @@ func ForkRepo(client *Client, repo ghrepo.Interface, org, newName string) (*Repo
 	if newName != "" {
 		params["name"] = newName
 	}
+	if defaultBranchOnly {
+		params["default_branch_only"] = true
+	}
 
 	body := &bytes.Buffer{}
 	enc := json.NewEncoder(body)
diff --git a/pkg/cmd/pr/create/create.go b/pkg/cmd/pr/create/create.go
index 2bdf47208..ca10bafea 100644
--- a/pkg/cmd/pr/create/create.go
+++ b/pkg/cmd/pr/create/create.go
@@ -698,7 +698,7 @@ func handlePush(opts CreateOptions, ctx CreateContext) error {
 	// one by forking the base repository
 	if headRepo == nil && ctx.IsPushEnabled {
 		opts.IO.StartProgressIndicator()
-		headRepo, err = api.ForkRepo(client, ctx.BaseRepo, "", "")
+		headRepo, err = api.ForkRepo(client, ctx.BaseRepo, "", "", false)
 		opts.IO.StopProgressIndicator()
 		if err != nil {
 			return fmt.Errorf("error forking repo: %w", err)
diff --git a/pkg/cmd/repo/fork/fork.go b/pkg/cmd/repo/fork/fork.go
index e17e4b34d..9ac196617 100644
--- a/pkg/cmd/repo/fork/fork.go
+++ b/pkg/cmd/repo/fork/fork.go
@@ -33,16 +33,17 @@ type ForkOptions struct {
 	Remotes    func() (ghContext.Remotes, error)
 	Since      func(time.Time) time.Duration
 
-	GitArgs      []string
-	Repository   string
-	Clone        bool
-	Remote       bool
-	PromptClone  bool
-	PromptRemote bool
-	RemoteName   string
-	Organization string
-	ForkName     string
-	Rename       bool
+	GitArgs           []string
+	Repository        string
+	Clone             bool
+	Remote            bool
+	PromptClone       bool
+	PromptRemote      bool
+	RemoteName        string
+	Organization      string
+	ForkName          string
+	Rename            bool
+	DefaultBranchOnly bool
 }
 
 // TODO warn about useless flags (--remote, --remote-name) when running from outside a repository
@@ -122,6 +123,7 @@ func NewCmdFork(f *cmdutil.Factory, runF func(*ForkOptions) error) *cobra.Comman
 	cmd.Flags().StringVar(&opts.RemoteName, "remote-name", defaultRemoteName, "Specify the name for the new remote")
 	cmd.Flags().StringVar(&opts.Organization, "org", "", "Create the fork in an organization")
 	cmd.Flags().StringVar(&opts.ForkName, "fork-name", "", "Rename the forked repository")
+	cmd.Flags().BoolVar(&opts.DefaultBranchOnly, "default-branch-only", false, "Only include the default branch in the fork")
 
 	return cmd
 }
@@ -181,7 +183,7 @@ func forkRun(opts *ForkOptions) error {
 	apiClient := api.NewClientFromHTTP(httpClient)
 
 	opts.IO.StartProgressIndicator()
-	forkedRepo, err := api.ForkRepo(apiClient, repoToFork, opts.Organization, opts.ForkName)
+	forkedRepo, err := api.ForkRepo(apiClient, repoToFork, opts.Organization, opts.ForkName, opts.DefaultBranchOnly)
 	opts.IO.StopProgressIndicator()
 	if err != nil {
 		return fmt.Errorf("failed to fork: %w", err)