diff --git a/hermes_cli/gateway.py b/hermes_cli/gateway.py
index 3b828fecf59..b3b58d5dbd4 100644
--- a/hermes_cli/gateway.py
+++ b/hermes_cli/gateway.py
@@ -1437,6 +1437,17 @@ def get_python_path() -> str:
             venv_python = venv / "bin" / "python"
         if venv_python.exists():
             return str(venv_python)
+    
+    # Fallback: use PROJECT_ROOT/venv/bin/python (same logic as generate_systemd_unit)
+    # This is more reliable than sys.executable when running under uv.
+    fallback_venv = PROJECT_ROOT / "venv"
+    if is_windows():
+        fallback_python = fallback_venv / "Scripts" / "python.exe"
+    else:
+        fallback_python = fallback_venv / "bin" / "python"
+    if fallback_python.exists():
+        return str(fallback_python)
+    
     return sys.executable
 
 
diff --git a/tests/hermes_cli/test_gateway_python_path.py b/tests/hermes_cli/test_gateway_python_path.py
new file mode 100644
index 00000000000..952ce90127f
--- /dev/null
+++ b/tests/hermes_cli/test_gateway_python_path.py
@@ -0,0 +1,152 @@
+"""Test for get_python_path() fallback to PROJECT_ROOT/venv/bin/python.
+
+Issue: #9201 - systemd service ExecStart uses uv Python instead of venv Python
+when uv manages the Python environment.
+
+Root cause: get_python_path() fell back to sys.executable when _detect_venv_dir()
+returned None, but this returns uv's Python path which has no packages installed.
+"""
+
+import sys
+import pytest
+from pathlib import Path
+from unittest.mock import patch, MagicMock
+
+
+class TestGetPythonPathFallback:
+    """Test that get_python_path() correctly falls back to PROJECT_ROOT/venv."""
+
+    def test_fallback_to_project_root_venv_when_detect_fails(self):
+        """When _detect_venv_dir() returns None, should use PROJECT_ROOT/venv."""
+        from hermes_cli.gateway import get_python_path, PROJECT_ROOT
+        
+        # Mock _detect_venv_dir to return None (simulate uv environment)
+        with patch("hermes_cli.gateway._detect_venv_dir", return_value=None):
+            # Mock the venv python to exist
+            with patch.object(Path, "exists", return_value=True):
+                result = get_python_path()
+                
+                # Should be PROJECT_ROOT/venv/bin/python, not sys.executable
+                expected = str(PROJECT_ROOT / "venv" / "bin" / "python")
+                assert result == expected
+
+    def test_detect_venv_dir_returns_valid_venv(self):
+        """When _detect_venv_dir() returns a valid venv, should use it."""
+        from hermes_cli.gateway import get_python_path
+        
+        # Mock _detect_venv_dir to return a venv
+        mock_venv = MagicMock(spec=Path)
+        mock_venv.is_dir.return_value = True
+        
+        with patch("hermes_cli.gateway._detect_venv_dir", return_value=mock_venv):
+            # Mock the venv python to exist
+            mock_python = MagicMock(spec=Path)
+            mock_python.exists.return_value = True
+            
+            with patch.object(Path, "__truediv__", return_value=mock_python):
+                result = get_python_path()
+                
+                # Should return the venv python path
+                assert result is not None
+
+    def test_fallback_chain_order(self):
+        """Fallback order should be: detected_venv -> PROJECT_ROOT/venv -> sys.executable."""
+        from hermes_cli.gateway import get_python_path, PROJECT_ROOT
+        
+        # Test 1: detected_venv has priority
+        mock_venv = MagicMock(spec=Path)
+        mock_venv_python = MagicMock(spec=Path)
+        mock_venv_python.exists.return_value = True
+        
+        with patch("hermes_cli.gateway._detect_venv_dir", return_value=mock_venv):
+            with patch.object(Path, "__truediv__", return_value=mock_venv_python):
+                result = get_python_path()
+                # Should use detected_venv, not PROJECT_ROOT fallback
+        
+        # Test 2: PROJECT_ROOT/venv fallback when detect fails but venv exists
+        with patch("hermes_cli.gateway._detect_venv_dir", return_value=None):
+            with patch.object(Path, "exists", return_value=True):
+                result = get_python_path()
+                expected = str(PROJECT_ROOT / "venv" / "bin" / "python")
+                assert result == expected
+        
+        # Test 3: sys.executable when all fallbacks fail
+        with patch("hermes_cli.gateway._detect_venv_dir", return_value=None):
+            with patch.object(Path, "exists", return_value=False):
+                result = get_python_path()
+                assert result == sys.executable
+
+    def test_consistency_with_venv_dir_in_systemd_unit(self):
+        """python_path should be consistent with venv_dir in generate_systemd_unit."""
+        from hermes_cli.gateway import (
+            get_python_path,
+            generate_systemd_unit,
+            PROJECT_ROOT,
+            _detect_venv_dir,
+        )
+        
+        # Simulate scenario where _detect_venv_dir returns None
+        with patch("hermes_cli.gateway._detect_venv_dir", return_value=None):
+            with patch.object(Path, "exists", return_value=True):
+                python_path = get_python_path()
+                unit = generate_systemd_unit(system=False)
+                
+                # python_path should match venv/bin/python in ExecStart
+                assert "venv/bin/python" in python_path
+                assert python_path in unit
+
+    def test_windows_fallback_uses_scripts_python_exe(self):
+        """On Windows, fallback should use venv/Scripts/python.exe."""
+        from hermes_cli.gateway import get_python_path, PROJECT_ROOT
+        
+        with patch("hermes_cli.gateway._detect_venv_dir", return_value=None):
+            with patch("hermes_cli.gateway.is_windows", return_value=True):
+                with patch.object(Path, "exists", return_value=True):
+                    result = get_python_path()
+                    expected = str(PROJECT_ROOT / "venv" / "Scripts" / "python.exe")
+                    assert result == expected
+
+    def test_execstart_not_uv_python_path(self):
+        """ExecStart should NOT contain uv Python path patterns."""
+        from hermes_cli.gateway import generate_systemd_unit
+        
+        with patch("hermes_cli.gateway._detect_venv_dir", return_value=None):
+            with patch.object(Path, "exists", return_value=True):
+                unit = generate_systemd_unit(system=False)
+                
+                # Should NOT have uv-specific paths
+                assert ".local/share/uv/python" not in unit
+                assert "cpython-" not in unit
+                # Should have venv path
+                assert "venv/bin/python" in unit
+
+
+class TestSystemdUnitGeneration:
+    """Test systemd unit file generation with correct Python path."""
+
+    def test_system_unit_execstart_uses_venv_python(self):
+        """System unit ExecStart should use venv/bin/python."""
+        from hermes_cli.gateway import generate_systemd_unit, PROJECT_ROOT
+        
+        with patch("hermes_cli.gateway._detect_venv_dir", return_value=None):
+            with patch.object(Path, "exists", return_value=True):
+                unit = generate_systemd_unit(system=True, run_as_user="root")
+                
+                # ExecStart should contain venv/bin/python
+                assert "venv/bin/python" in unit
+                assert "ExecStart=" in unit
+
+    def test_user_unit_execstart_uses_venv_python(self):
+        """User unit ExecStart should use venv/bin/python."""
+        from hermes_cli.gateway import generate_systemd_unit, PROJECT_ROOT
+        
+        with patch("hermes_cli.gateway._detect_venv_dir", return_value=None):
+            with patch.object(Path, "exists", return_value=True):
+                unit = generate_systemd_unit(system=False)
+                
+                # ExecStart should contain venv/bin/python
+                assert "venv/bin/python" in unit
+
+
+if __name__ == "__main__":
+    pytest.main([__file__, "-v"])
\ No newline at end of file