diff --git a/pkg/cmd/codespace/root.go b/pkg/cmd/codespace/root.go
index 0a04d2fdd..662f4c2de 100644
--- a/pkg/cmd/codespace/root.go
+++ b/pkg/cmd/codespace/root.go
@@ -20,6 +20,7 @@ func NewRootCmd(app *App) *cobra.Command {
 	root.AddCommand(newSSHCmd(app))
 	root.AddCommand(newCpCmd(app))
 	root.AddCommand(newStopCmd(app))
+	root.AddCommand(newSelectCmd(app))
 
 	return root
 }
diff --git a/pkg/cmd/codespace/select.go b/pkg/cmd/codespace/select.go
new file mode 100644
index 000000000..d95162c12
--- /dev/null
+++ b/pkg/cmd/codespace/select.go
@@ -0,0 +1,75 @@
+package codespace
+
+import (
+	"context"
+	"fmt"
+	"os"
+
+	"github.com/spf13/cobra"
+)
+
+type selectOptions struct {
+	filePath string
+}
+
+func newSelectCmd(app *App) *cobra.Command {
+	opts := selectOptions{}
+
+	selectCmd := &cobra.Command{
+		Use:    "select",
+		Short:  "Select a Codespace",
+		Hidden: true,
+		Args:   noArgsConstraint,
+		RunE: func(cmd *cobra.Command, args []string) error {
+			return app.Select(cmd.Context(), "", opts)
+		},
+	}
+
+	selectCmd.Flags().StringVarP(&opts.filePath, "file", "f", "", "Output file path")
+	return selectCmd
+}
+
+// Hidden codespace `select` command allows to reuse existing codespace selection
+// dialog by external GH CLI extensions. By default output selected codespace name
+// into `stdout`. Pass `--file`(`-f`) flag along with a file path to output selected
+// codespace name into a file instead.
+//
+// ## Examples
+//
+// With `stdout` output:
+//
+// ```shell
+// 		gh codespace select
+// ```
+//
+// With `into-a-file` output:
+//
+// ```shell
+// 		gh codespace select --file /tmp/selected_codespace.txt
+// ```
+func (a *App) Select(ctx context.Context, name string, opts selectOptions) (err error) {
+	codespace, err := getOrChooseCodespace(ctx, a.apiClient, name)
+	if err != nil {
+		return err
+	}
+
+	if opts.filePath != "" {
+		f, err := os.Create(opts.filePath)
+		if err != nil {
+			return fmt.Errorf("failed to create output file: %w", err)
+		}
+
+		defer safeClose(f, &err)
+
+		_, err = f.WriteString(codespace.Name)
+		if err != nil {
+			return fmt.Errorf("failed to write codespace name to output file: %w", err)
+		}
+
+		return nil
+	}
+
+	fmt.Fprintln(a.io.Out, codespace.Name)
+
+	return nil
+}
diff --git a/pkg/cmd/codespace/select_test.go b/pkg/cmd/codespace/select_test.go
new file mode 100644
index 000000000..b2253f1d4
--- /dev/null
+++ b/pkg/cmd/codespace/select_test.go
@@ -0,0 +1,107 @@
+package codespace
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"io/ioutil"
+	"os"
+	"testing"
+
+	"github.com/cli/cli/v2/internal/codespaces/api"
+	"github.com/cli/cli/v2/pkg/iostreams"
+)
+
+const CODESPACE_NAME = "monalisa-cli-cli-abcdef"
+
+func TestApp_Select(t *testing.T) {
+	tests := []struct {
+		name             string
+		arg              string
+		wantErr          bool
+		outputToFile     bool
+		wantStdout       string
+		wantStderr       string
+		wantFileContents string
+	}{
+		{
+			name:       "Select a codespace",
+			arg:        CODESPACE_NAME,
+			wantErr:    false,
+			wantStdout: fmt.Sprintf("%s\n", CODESPACE_NAME),
+		},
+		{
+			name:    "Select a codespace error",
+			arg:     "non-existent-codespace-name",
+			wantErr: true,
+		},
+		{
+			name:             "Select a codespace",
+			arg:              CODESPACE_NAME,
+			wantErr:          false,
+			wantFileContents: CODESPACE_NAME,
+			outputToFile:     true,
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			io, _, stdout, stderr := iostreams.Test()
+			io.SetStdinTTY(true)
+			io.SetStdoutTTY(true)
+			a := NewApp(io, nil, testSelectApiMock(), nil)
+
+			opts := selectOptions{}
+			if tt.outputToFile {
+				file, err := ioutil.TempFile("", "codespace-selection-test")
+				if err != nil {
+					t.Fatal(err)
+				}
+
+				defer os.Remove(file.Name())
+
+				opts = selectOptions{filePath: file.Name()}
+			}
+
+			if err := a.Select(context.Background(), tt.arg, opts); (err != nil) != tt.wantErr {
+				t.Errorf("App.Select() error = %v, wantErr %v", err, tt.wantErr)
+			}
+
+			if out := stdout.String(); out != tt.wantStdout {
+				t.Errorf("stdout = %q, want %q", out, tt.wantStdout)
+			}
+			if out := sortLines(stderr.String()); out != tt.wantStderr {
+				t.Errorf("stderr = %q, want %q", out, tt.wantStderr)
+			}
+
+			if tt.wantFileContents != "" {
+				if opts.filePath == "" {
+					t.Errorf("wantFileContents is set but opts.filePath is not")
+				}
+
+				dat, err := os.ReadFile(opts.filePath)
+				if err != nil {
+					t.Fatal(err)
+				}
+
+				if string(dat) != tt.wantFileContents {
+					t.Errorf("file contents = %q, want %q", string(dat), CODESPACE_NAME)
+				}
+			}
+		})
+	}
+}
+
+func testSelectApiMock() *apiClientMock {
+	testingCodespace := &api.Codespace{
+		Name: CODESPACE_NAME,
+	}
+	return &apiClientMock{
+		GetCodespaceFunc: func(_ context.Context, name string, includeConnection bool) (*api.Codespace, error) {
+			if name == CODESPACE_NAME {
+				return testingCodespace, nil
+			}
+
+			return nil, errors.New("cannot find codespace")
+		},
+	}
+}