diff --git a/paasta_tools/cli/cmds/list_namespaces.py b/paasta_tools/cli/cmds/list_namespaces.py
index fac36846cd..e5ed945925 100644
--- a/paasta_tools/cli/cmds/list_namespaces.py
+++ b/paasta_tools/cli/cmds/list_namespaces.py
@@ -15,6 +15,7 @@
 from paasta_tools.cli.utils import get_instance_configs_for_service
 from paasta_tools.cli.utils import lazy_choices_completer
 from paasta_tools.cli.utils import validate_service_name
+from paasta_tools.spark_tools import SPARK_EXECUTOR_NAMESPACE
 from paasta_tools.utils import DEFAULT_SOA_DIR
 from paasta_tools.utils import list_clusters
 from paasta_tools.utils import list_services
@@ -69,8 +70,14 @@ def paasta_list_namespaces(args):
         # We skip non-k8s instance types
         if instance.get_instance_type() in ("paasta-native", "adhoc"):
             continue
-        else:
-            namespaces.add(instance.get_namespace())
+        namespaces.add(instance.get_namespace())
+        # Tron instances are TronActionConfigs
+        if (
+            instance.get_instance_type() == "tron"
+            and instance.get_executor() == "spark"
+        ):
+            # We also need paasta-spark for spark executors
+            namespaces.add(SPARK_EXECUTOR_NAMESPACE)
 
     # Print in list format to be used in iam_roles
     print(list(namespaces))
diff --git a/tests/cli/test_cmds_list_namespaces.py b/tests/cli/test_cmds_list_namespaces.py
index eb9bb635dc..eeb03910df 100644
--- a/tests/cli/test_cmds_list_namespaces.py
+++ b/tests/cli/test_cmds_list_namespaces.py
@@ -3,6 +3,7 @@
 from mock import patch
 
 from paasta_tools.cli.cmds.list_namespaces import paasta_list_namespaces
+from paasta_tools.spark_tools import SPARK_EXECUTOR_NAMESPACE
 
 
 def test_list_namespaces_no_instances(capfd):
@@ -39,13 +40,14 @@ def create_mock_instance_config(instance_type, namespace):
     return mock_instance_config
 
 
-def test_list_namespaces_with_instances(capfd):
+def test_list_namespaces_with_instances_dupe_ns(capfd):
     mock_args = MagicMock(
         service="fake_service",
         instance=None,
         cluster=None,
         soa_dir="/fake/soa/dir",
     )
+
     mock_instance_configs = [
         create_mock_instance_config("kubernetes", "k8s_namespace"),
         create_mock_instance_config("kubernetes", "k8s_namespace"),
@@ -64,6 +66,59 @@ def test_list_namespaces_with_instances(capfd):
         assert stdout.strip() == "['k8s_namespace']"
 
 
+def test_list_namespaces_tron(capfd):
+    mock_args = MagicMock(
+        service="fake_service",
+        instance=None,
+        cluster=None,
+        soa_dir="/fake/soa/dir",
+    )
+    mock_tron_instance = create_mock_instance_config("tron", "tron")
+    mock_tron_instance.get_executor.return_value = "paasta"
+
+    with patch(
+        "paasta_tools.cli.cmds.list_namespaces.get_instance_configs_for_service",
+        return_value=[mock_tron_instance],
+        autospec=True,
+    ), patch(
+        "paasta_tools.cli.cmds.list_namespaces.validate_service_name",
+        autospec=True,
+    ):
+        assert paasta_list_namespaces(mock_args) == 0
+        stdout, _ = capfd.readouterr()
+        assert "['tron']"
+
+
+def test_list_namespaces_spark(capfd):
+    mock_args = MagicMock(
+        service="fake_service",
+        instance=None,
+        cluster=None,
+        soa_dir="/fake/soa/dir",
+    )
+    mock_spark_instance = create_mock_instance_config("tron", "tron")
+    mock_spark_instance.get_executor.return_value = "spark"
+
+    mock_instance_configs = [
+        create_mock_instance_config("kubernetes", "k8s_namespace"),
+        mock_spark_instance,
+    ]
+
+    with patch(
+        "paasta_tools.cli.cmds.list_namespaces.get_instance_configs_for_service",
+        return_value=mock_instance_configs,
+        autospec=True,
+    ), patch(
+        "paasta_tools.cli.cmds.list_namespaces.validate_service_name",
+        autospec=True,
+    ):
+        assert paasta_list_namespaces(mock_args) == 0
+        stdout, _ = capfd.readouterr()
+        assert f"'{SPARK_EXECUTOR_NAMESPACE}'" in stdout
+        assert "'tron'" in stdout
+        assert "'k8s_namespace'" in stdout
+
+
 def test_list_namespaces_skips_non_k8s_instances(capfd):
     mock_args = MagicMock(
         service="fake_service",