diff --git a/homeassistant/helpers/config_validation.py b/homeassistant/helpers/config_validation.py
index 4bfcb98e9d4..8f0c93f5c9f 100644
--- a/homeassistant/helpers/config_validation.py
+++ b/homeassistant/helpers/config_validation.py
@@ -929,8 +929,10 @@ SERVICE_SCHEMA = vol.All(
             vol.Exclusive(CONF_SERVICE_TEMPLATE, "service name"): vol.Any(
                 service, dynamic_template
             ),
-            vol.Optional("data"): vol.All(dict, template_complex),
-            vol.Optional("data_template"): vol.All(dict, template_complex),
+            vol.Optional("data"): vol.Any(template, vol.All(dict, template_complex)),
+            vol.Optional("data_template"): vol.Any(
+                template, vol.All(dict, template_complex)
+            ),
             vol.Optional(CONF_ENTITY_ID): comp_entity_ids,
             vol.Optional(CONF_TARGET): vol.Any(ENTITY_SERVICE_FIELDS, dynamic_template),
         }
diff --git a/homeassistant/helpers/service.py b/homeassistant/helpers/service.py
index 57bcefe56e3..c2720c02f47 100644
--- a/homeassistant/helpers/service.py
+++ b/homeassistant/helpers/service.py
@@ -234,7 +234,12 @@ def async_prepare_call_from_config(
             continue
         try:
             template.attach(hass, config[conf])
-            service_data.update(template.render_complex(config[conf], variables))
+            render = template.render_complex(config[conf], variables)
+            if not isinstance(render, dict):
+                raise HomeAssistantError(
+                    "Error rendering data template: Result is not a Dictionary"
+                )
+            service_data.update(render)
         except TemplateError as ex:
             raise HomeAssistantError(f"Error rendering data template: {ex}") from ex
 
diff --git a/tests/components/automation/test_init.py b/tests/components/automation/test_init.py
index 214b2ea20e8..b90c6a90819 100644
--- a/tests/components/automation/test_init.py
+++ b/tests/components/automation/test_init.py
@@ -45,9 +45,9 @@ def calls(hass):
     return async_mock_service(hass, "test", "automation")
 
 
-async def test_service_data_not_a_dict(hass, calls):
+async def test_service_data_not_a_dict(hass, caplog, calls):
     """Test service data not dict."""
-    with assert_setup_component(0, automation.DOMAIN):
+    with assert_setup_component(1, automation.DOMAIN):
         assert await async_setup_component(
             hass,
             automation.DOMAIN,
@@ -59,6 +59,34 @@ async def test_service_data_not_a_dict(hass, calls):
             },
         )
 
+    hass.bus.async_fire("test_event")
+    await hass.async_block_till_done()
+    assert len(calls) == 0
+    assert "Result is not a Dictionary" in caplog.text
+
+
+async def test_service_data_single_template(hass, calls):
+    """Test service data not dict."""
+    with assert_setup_component(1, automation.DOMAIN):
+        assert await async_setup_component(
+            hass,
+            automation.DOMAIN,
+            {
+                automation.DOMAIN: {
+                    "trigger": {"platform": "event", "event_type": "test_event"},
+                    "action": {
+                        "service": "test.automation",
+                        "data": "{{ { 'foo': 'bar' } }}",
+                    },
+                }
+            },
+        )
+
+    hass.bus.async_fire("test_event")
+    await hass.async_block_till_done()
+    assert len(calls) == 1
+    assert calls[0].data["foo"] == "bar"
+
 
 async def test_service_specify_data(hass, calls):
     """Test service data."""