diff --git a/src/ci_orchestrator/commands/vm.py b/src/ci_orchestrator/commands/vm.py
index e1911dc..15761cf 100644
--- a/src/ci_orchestrator/commands/vm.py
+++ b/src/ci_orchestrator/commands/vm.py
@@ -12,7 +12,9 @@ instead of scanning the local filesystem.
 
 from __future__ import annotations
 
+import os
 import shutil
+import subprocess
 import time
 from datetime import UTC, datetime, timedelta
 from pathlib import Path
@@ -483,4 +485,116 @@ def vm_new(
     click.echo(handle.identifier)
 
 
+# ────────────────────────────────────────────────────────────────────────── open
+
+
+def _launch_gui(argv: list[str], env: dict[str, str]) -> int:
+    """Spawn the VMware Workstation GUI detached. Returns the child PID.
+
+    Isolated so tests can monkeypatch it without spawning a real process. The
+    GUI must outlive the CLI, so the child is started in its own session with
+    its stdio detached.
+    """
+    proc = subprocess.Popen(  # argv is a fixed list, never a shell string
+        argv,
+        env=env,
+        stdin=subprocess.DEVNULL,
+        stdout=subprocess.DEVNULL,
+        stderr=subprocess.DEVNULL,
+        start_new_session=True,
+    )
+    return proc.pid
+
+
+@vm.command("open")
+@click.option(
+    "--vmx",
+    "--vm-path",
+    "vmx",
+    required=True,
+    help="Path to the VMX file to open in the VMware Workstation GUI.",
+)
+@click.option(
+    "--vmware-path",
+    "vmware_path",
+    default="vmware",
+    show_default=True,
+    help="Path to the VMware Workstation GUI binary.",
+)
+@click.option(
+    "--power-on",
+    "power_on",
+    is_flag=True,
+    default=False,
+    help="Power the VM on when it is opened (vmware -x).",
+)
+@click.option(
+    "--fullscreen",
+    is_flag=True,
+    default=False,
+    help="Power on and enter full-screen mode (vmware -X). Implies --power-on.",
+)
+@click.option(
+    "--new-window",
+    "new_window",
+    is_flag=True,
+    default=False,
+    help="Open in a new window instead of a tab (vmware -n).",
+)
+@click.option(
+    "--display",
+    "display",
+    default=None,
+    help="X display to use (default: inherit $DISPLAY). e.g. ':0'.",
+)
+def vm_open(
+    vmx: str,
+    vmware_path: str,
+    power_on: bool,
+    fullscreen: bool,
+    new_window: bool,
+    display: str | None,
+) -> None:
+    """Open a VMX in the VMware Workstation GUI (run as the ci-runner user).
+
+    Launches the interactive GUI — unlike the headless ``vmrun`` path the rest
+    of the orchestrator uses. The GUI needs an X display: when invoked through
+    ``sudo -u ci-runner`` the display is usually stripped, so authorise the
+    service user first, e.g. ``xhost +SI:localuser:ci-runner``, and pass
+    ``--display :0`` (or export ``DISPLAY``).
+    """
+    vmx_path = Path(vmx)
+    if not vmx_path.is_file():
+        raise click.ClickException(f"VMX file not found: {vmx}")
+
+    gui = shutil.which(vmware_path) or vmware_path
+
+    env = dict(os.environ)
+    if display:
+        env["DISPLAY"] = display
+    if not env.get("DISPLAY"):
+        click.echo(
+            "[vm open] WARNING: no X display set ($DISPLAY empty and --display "
+            "omitted). The GUI will fail to start. Pass --display :0 and run "
+            "`xhost +SI:localuser:ci-runner` from a desktop session first.",
+            err=True,
+        )
+
+    argv = [gui]
+    if new_window:
+        argv.append("-n")
+    if fullscreen:
+        argv.append("-X")
+    elif power_on:
+        argv.append("-x")
+    argv.append(str(vmx_path))
+
+    click.echo(f"[vm open] launching VMware GUI: {' '.join(argv)}")
+    try:
+        pid = _launch_gui(argv, env)
+    except (OSError, ValueError) as exc:
+        raise click.ClickException(f"failed to launch VMware GUI: {exc}") from exc
+    click.echo(f"[vm open] VMware GUI started (pid {pid}); display={env.get('DISPLAY', '')}")
+
+
 __all__ = ["cleanup_orphans", "vm"]
diff --git a/tests/python/test_commands_vm.py b/tests/python/test_commands_vm.py
index 172863d..18fb5e7 100644
--- a/tests/python/test_commands_vm.py
+++ b/tests/python/test_commands_vm.py
@@ -497,3 +497,94 @@ def test_vm_cleanup_backend_unavailable(monkeypatch: pytest.MonkeyPatch, tmp_pat
     )
     assert result.exit_code == 0
     assert "vmrun not available" in result.output
+
+
+# ── vm open ───────────────────────────────────────────────────────────────────
+
+
+def _capture_launch(monkeypatch: pytest.MonkeyPatch) -> dict[str, Any]:
+    """Patch _launch_gui to record argv/env instead of spawning a process."""
+    captured: dict[str, Any] = {}
+
+    def _fake(argv: list[str], env: dict[str, str]) -> int:
+        captured["argv"] = argv
+        captured["env"] = env
+        return 4242
+
+    monkeypatch.setattr(vm_module, "_launch_gui", _fake)
+    return captured
+
+
+def test_vm_open_missing_vmx_errors(tmp_path: Path) -> None:
+    result = CliRunner().invoke(cli, ["vm", "open", "--vmx", str(tmp_path / "nope.vmx")])
+    assert result.exit_code != 0
+    assert "VMX file not found" in result.output
+
+
+def test_vm_open_happy_path(monkeypatch: pytest.MonkeyPatch, tmp_path: Path) -> None:
+    vmx = tmp_path / "clone.vmx"
+    vmx.write_text("config")
+    cap = _capture_launch(monkeypatch)
+    monkeypatch.setenv("DISPLAY", ":0")
+    result = CliRunner().invoke(cli, ["vm", "open", "--vmx", str(vmx)])
+    assert result.exit_code == 0, result.output
+    assert cap["argv"][-1] == str(vmx)
+    assert "-x" not in cap["argv"] and "-X" not in cap["argv"]
+    assert "pid 4242" in result.output
+
+
+def test_vm_open_power_on_adds_x(monkeypatch: pytest.MonkeyPatch, tmp_path: Path) -> None:
+    vmx = tmp_path / "clone.vmx"
+    vmx.write_text("config")
+    cap = _capture_launch(monkeypatch)
+    monkeypatch.setenv("DISPLAY", ":0")
+    result = CliRunner().invoke(cli, ["vm", "open", "--vmx", str(vmx), "--power-on"])
+    assert result.exit_code == 0, result.output
+    assert "-x" in cap["argv"]
+
+
+def test_vm_open_fullscreen_adds_capital_x(monkeypatch: pytest.MonkeyPatch, tmp_path: Path) -> None:
+    vmx = tmp_path / "clone.vmx"
+    vmx.write_text("config")
+    cap = _capture_launch(monkeypatch)
+    monkeypatch.setenv("DISPLAY", ":0")
+    result = CliRunner().invoke(
+        cli, ["vm", "open", "--vmx", str(vmx), "--fullscreen", "--new-window"]
+    )
+    assert result.exit_code == 0, result.output
+    assert "-X" in cap["argv"] and "-n" in cap["argv"]
+
+
+def test_vm_open_display_option_overrides_env(monkeypatch: pytest.MonkeyPatch, tmp_path: Path) -> None:
+    vmx = tmp_path / "clone.vmx"
+    vmx.write_text("config")
+    cap = _capture_launch(monkeypatch)
+    monkeypatch.delenv("DISPLAY", raising=False)
+    result = CliRunner().invoke(cli, ["vm", "open", "--vmx", str(vmx), "--display", ":1"])
+    assert result.exit_code == 0, result.output
+    assert cap["env"]["DISPLAY"] == ":1"
+    assert "display=:1" in result.output
+
+
+def test_vm_open_warns_without_display(monkeypatch: pytest.MonkeyPatch, tmp_path: Path) -> None:
+    vmx = tmp_path / "clone.vmx"
+    vmx.write_text("config")
+    _capture_launch(monkeypatch)
+    monkeypatch.delenv("DISPLAY", raising=False)
+    result = CliRunner().invoke(cli, ["vm", "open", "--vmx", str(vmx)])
+    assert result.exit_code == 0, result.output
+    assert "no X display" in result.output
+
+
+def test_vm_open_launch_failure_is_reported(monkeypatch: pytest.MonkeyPatch, tmp_path: Path) -> None:
+    vmx = tmp_path / "clone.vmx"
+    vmx.write_text("config")
+
+    def _boom(argv: list[str], env: dict[str, str]) -> int:
+        raise OSError("vmware not found")
+
+    monkeypatch.setattr(vm_module, "_launch_gui", _boom)
+    monkeypatch.setenv("DISPLAY", ":0")
+    result = CliRunner().invoke(cli, ["vm", "open", "--vmx", str(vmx)])
+    assert result.exit_code != 0
+    assert "failed to launch VMware GUI" in result.output