diff --git a/homeassistant/components/conversation/__init__.py b/homeassistant/components/conversation/__init__.py
index 29dd56c11ec..193bd45bba0 100644
--- a/homeassistant/components/conversation/__init__.py
+++ b/homeassistant/components/conversation/__init__.py
@@ -42,6 +42,7 @@ _LOGGER = logging.getLogger(__name__)
 ATTR_TEXT = "text"
 ATTR_LANGUAGE = "language"
 ATTR_AGENT_ID = "agent_id"
+ATTR_CONVERSATION_ID = "conversation_id"
 
 DOMAIN = "conversation"
 
@@ -66,6 +67,7 @@ SERVICE_PROCESS_SCHEMA = vol.Schema(
         vol.Required(ATTR_TEXT): cv.string,
         vol.Optional(ATTR_LANGUAGE): cv.string,
         vol.Optional(ATTR_AGENT_ID): agent_id_validator,
+        vol.Optional(ATTR_CONVERSATION_ID): cv.string,
     }
 )
 
@@ -164,7 +166,7 @@ async def async_setup(hass: HomeAssistant, config: ConfigType) -> bool:
             result = await async_converse(
                 hass=hass,
                 text=text,
-                conversation_id=None,
+                conversation_id=service.data.get(ATTR_CONVERSATION_ID),
                 context=service.context,
                 language=service.data.get(ATTR_LANGUAGE),
                 agent_id=service.data.get(ATTR_AGENT_ID),
diff --git a/homeassistant/components/conversation/services.yaml b/homeassistant/components/conversation/services.yaml
index 953db065614..3846426c3f0 100644
--- a/homeassistant/components/conversation/services.yaml
+++ b/homeassistant/components/conversation/services.yaml
@@ -14,6 +14,10 @@ process:
       example: homeassistant
       selector:
         conversation_agent:
+    conversation_id:
+      example: my_conversation_1
+      selector:
+        text:
 
 reload:
   fields:
diff --git a/homeassistant/components/conversation/strings.json b/homeassistant/components/conversation/strings.json
index 8240cfa3f82..255e6cec430 100644
--- a/homeassistant/components/conversation/strings.json
+++ b/homeassistant/components/conversation/strings.json
@@ -16,6 +16,10 @@
         "agent_id": {
           "name": "Agent",
           "description": "Conversation agent to process your request. The conversation agent is the brains of your assistant. It processes the incoming text commands."
+        },
+        "conversation_id": {
+          "name": "Conversation ID",
+          "description": "ID of the conversation, to be able to continue a previous conversation"
         }
       }
     },
diff --git a/tests/components/conversation/snapshots/test_init.ambr b/tests/components/conversation/snapshots/test_init.ambr
index 35d967f37da..7f928224aba 100644
--- a/tests/components/conversation/snapshots/test_init.ambr
+++ b/tests/components/conversation/snapshots/test_init.ambr
@@ -225,7 +225,7 @@
     ]),
   })
 # ---
-# name: test_turn_on_intent[turn kitchen on-None]
+# name: test_turn_on_intent[None-turn kitchen on-None]
   dict({
     'conversation_id': None,
     'response': dict({
@@ -255,7 +255,7 @@
     }),
   })
 # ---
-# name: test_turn_on_intent[turn kitchen on-homeassistant]
+# name: test_turn_on_intent[None-turn kitchen on-homeassistant]
   dict({
     'conversation_id': None,
     'response': dict({
@@ -285,7 +285,7 @@
     }),
   })
 # ---
-# name: test_turn_on_intent[turn on kitchen-None]
+# name: test_turn_on_intent[None-turn on kitchen-None]
   dict({
     'conversation_id': None,
     'response': dict({
@@ -315,7 +315,127 @@
     }),
   })
 # ---
-# name: test_turn_on_intent[turn on kitchen-homeassistant]
+# name: test_turn_on_intent[None-turn on kitchen-homeassistant]
+  dict({
+    'conversation_id': None,
+    'response': dict({
+      'card': dict({
+      }),
+      'data': dict({
+        'failed': list([
+        ]),
+        'success': list([
+          dict({
+            'id': 'light.kitchen',
+            'name': 'kitchen',
+            'type': <IntentResponseTargetType.ENTITY: 'entity'>,
+          }),
+        ]),
+        'targets': list([
+        ]),
+      }),
+      'language': 'en',
+      'response_type': 'action_done',
+      'speech': dict({
+        'plain': dict({
+          'extra_data': None,
+          'speech': 'Turned on light',
+        }),
+      }),
+    }),
+  })
+# ---
+# name: test_turn_on_intent[my_new_conversation-turn kitchen on-None]
+  dict({
+    'conversation_id': None,
+    'response': dict({
+      'card': dict({
+      }),
+      'data': dict({
+        'failed': list([
+        ]),
+        'success': list([
+          dict({
+            'id': 'light.kitchen',
+            'name': 'kitchen',
+            'type': <IntentResponseTargetType.ENTITY: 'entity'>,
+          }),
+        ]),
+        'targets': list([
+        ]),
+      }),
+      'language': 'en',
+      'response_type': 'action_done',
+      'speech': dict({
+        'plain': dict({
+          'extra_data': None,
+          'speech': 'Turned on light',
+        }),
+      }),
+    }),
+  })
+# ---
+# name: test_turn_on_intent[my_new_conversation-turn kitchen on-homeassistant]
+  dict({
+    'conversation_id': None,
+    'response': dict({
+      'card': dict({
+      }),
+      'data': dict({
+        'failed': list([
+        ]),
+        'success': list([
+          dict({
+            'id': 'light.kitchen',
+            'name': 'kitchen',
+            'type': <IntentResponseTargetType.ENTITY: 'entity'>,
+          }),
+        ]),
+        'targets': list([
+        ]),
+      }),
+      'language': 'en',
+      'response_type': 'action_done',
+      'speech': dict({
+        'plain': dict({
+          'extra_data': None,
+          'speech': 'Turned on light',
+        }),
+      }),
+    }),
+  })
+# ---
+# name: test_turn_on_intent[my_new_conversation-turn on kitchen-None]
+  dict({
+    'conversation_id': None,
+    'response': dict({
+      'card': dict({
+      }),
+      'data': dict({
+        'failed': list([
+        ]),
+        'success': list([
+          dict({
+            'id': 'light.kitchen',
+            'name': 'kitchen',
+            'type': <IntentResponseTargetType.ENTITY: 'entity'>,
+          }),
+        ]),
+        'targets': list([
+        ]),
+      }),
+      'language': 'en',
+      'response_type': 'action_done',
+      'speech': dict({
+        'plain': dict({
+          'extra_data': None,
+          'speech': 'Turned on light',
+        }),
+      }),
+    }),
+  })
+# ---
+# name: test_turn_on_intent[my_new_conversation-turn on kitchen-homeassistant]
   dict({
     'conversation_id': None,
     'response': dict({
diff --git a/tests/components/conversation/test_init.py b/tests/components/conversation/test_init.py
index 0f47f9ac3d9..820734901ad 100644
--- a/tests/components/conversation/test_init.py
+++ b/tests/components/conversation/test_init.py
@@ -873,8 +873,9 @@ async def test_http_processing_intent_conversion_not_expose_new(
 
 @pytest.mark.parametrize("agent_id", AGENT_ID_OPTIONS)
 @pytest.mark.parametrize("sentence", ("turn on kitchen", "turn kitchen on"))
+@pytest.mark.parametrize("conversation_id", ("my_new_conversation", None))
 async def test_turn_on_intent(
-    hass: HomeAssistant, init_components, sentence, agent_id, snapshot
+    hass: HomeAssistant, init_components, conversation_id, sentence, agent_id, snapshot
 ) -> None:
     """Test calling the turn on intent."""
     hass.states.async_set("light.kitchen", "off")
@@ -883,6 +884,8 @@ async def test_turn_on_intent(
     data = {conversation.ATTR_TEXT: sentence}
     if agent_id is not None:
         data[conversation.ATTR_AGENT_ID] = agent_id
+    if conversation_id is not None:
+        data[conversation.ATTR_CONVERSATION_ID] = conversation_id
     result = await hass.services.async_call(
         "conversation",
         "process",