diff --git a/homeassistant/components/assist_satellite/__init__.py b/homeassistant/components/assist_satellite/__init__.py
index 47b0123a244..038ff517264 100644
--- a/homeassistant/components/assist_satellite/__init__.py
+++ b/homeassistant/components/assist_satellite/__init__.py
@@ -63,6 +63,21 @@ async def async_setup(hass: HomeAssistant, config: ConfigType) -> bool:
         "async_internal_announce",
         [AssistSatelliteEntityFeature.ANNOUNCE],
     )
+    component.async_register_entity_service(
+        "start_conversation",
+        vol.All(
+            cv.make_entity_service_schema(
+                {
+                    vol.Optional("start_message"): str,
+                    vol.Optional("start_media_id"): str,
+                    vol.Optional("extra_system_prompt"): str,
+                }
+            ),
+            cv.has_at_least_one_key("start_message", "start_media_id"),
+        ),
+        "async_internal_start_conversation",
+        [AssistSatelliteEntityFeature.START_CONVERSATION],
+    )
     hass.data[CONNECTION_TEST_DATA] = {}
     async_register_websocket_api(hass)
     hass.http.register_view(ConnectionTestView())
diff --git a/homeassistant/components/assist_satellite/const.py b/homeassistant/components/assist_satellite/const.py
index 61ac7ecb39d..f7ac7e524b4 100644
--- a/homeassistant/components/assist_satellite/const.py
+++ b/homeassistant/components/assist_satellite/const.py
@@ -26,3 +26,6 @@ class AssistSatelliteEntityFeature(IntFlag):
 
     ANNOUNCE = 1
     """Device supports remotely triggered announcements."""
+
+    START_CONVERSATION = 2
+    """Device supports starting conversations."""
diff --git a/homeassistant/components/assist_satellite/entity.py b/homeassistant/components/assist_satellite/entity.py
index 8be136653ba..ad6d36ea521 100644
--- a/homeassistant/components/assist_satellite/entity.py
+++ b/homeassistant/components/assist_satellite/entity.py
@@ -10,7 +10,7 @@ import logging
 import time
 from typing import Any, Final, Literal, final
 
-from homeassistant.components import media_source, stt, tts
+from homeassistant.components import conversation, media_source, stt, tts
 from homeassistant.components.assist_pipeline import (
     OPTION_PREFERRED,
     AudioSettings,
@@ -27,6 +27,7 @@ from homeassistant.components.tts import (
     generate_media_source_id as tts_generate_media_source_id,
 )
 from homeassistant.core import Context, callback
+from homeassistant.exceptions import HomeAssistantError
 from homeassistant.helpers import entity
 from homeassistant.helpers.entity import EntityDescription
 
@@ -113,6 +114,7 @@ class AssistSatelliteEntity(entity.Entity):
 
     _run_has_tts: bool = False
     _is_announcing = False
+    _extra_system_prompt: str | None = None
     _wake_word_intercept_future: asyncio.Future[str | None] | None = None
     _attr_tts_options: dict[str, Any] | None = None
     _pipeline_task: asyncio.Task | None = None
@@ -212,6 +214,60 @@ class AssistSatelliteEntity(entity.Entity):
         """
         raise NotImplementedError
 
+    async def async_internal_start_conversation(
+        self,
+        start_message: str | None = None,
+        start_media_id: str | None = None,
+        extra_system_prompt: str | None = None,
+    ) -> None:
+        """Start a conversation from the satellite.
+
+        If start_media_id is not provided, message is synthesized to
+        audio with the selected pipeline.
+
+        If start_media_id is provided, it is played directly. It is possible
+        to omit the message and the satellite will not show any text.
+
+        Calls async_start_conversation.
+        """
+        await self._cancel_running_pipeline()
+
+        # The Home Assistant built-in agent doesn't support conversations.
+        pipeline = async_get_pipeline(self.hass, self._resolve_pipeline())
+        if pipeline.conversation_engine == conversation.HOME_ASSISTANT_AGENT:
+            raise HomeAssistantError(
+                "Built-in conversation agent does not support starting conversations"
+            )
+
+        if start_message is None:
+            start_message = ""
+
+        announcement = await self._resolve_announcement_media_id(
+            start_message, start_media_id
+        )
+
+        if self._is_announcing:
+            raise SatelliteBusyError
+
+        self._is_announcing = True
+        # Provide our start info to the LLM so it understands context of incoming message
+        if extra_system_prompt is not None:
+            self._extra_system_prompt = extra_system_prompt
+        else:
+            self._extra_system_prompt = start_message or None
+
+        try:
+            await self.async_start_conversation(announcement)
+        finally:
+            self._is_announcing = False
+            self._extra_system_prompt = None
+
+    async def async_start_conversation(
+        self, start_announcement: AssistSatelliteAnnouncement
+    ) -> None:
+        """Start a conversation from the satellite."""
+        raise NotImplementedError
+
     async def async_accept_pipeline_from_satellite(
         self,
         audio_stream: AsyncIterable[bytes],
@@ -298,6 +354,7 @@ class AssistSatelliteEntity(entity.Entity):
                 ),
                 start_stage=start_stage,
                 end_stage=end_stage,
+                conversation_extra_system_prompt=self._extra_system_prompt,
             ),
             f"{self.entity_id}_pipeline",
         )
diff --git a/homeassistant/components/assist_satellite/icons.json b/homeassistant/components/assist_satellite/icons.json
index a98c3aefc5b..1ed29541621 100644
--- a/homeassistant/components/assist_satellite/icons.json
+++ b/homeassistant/components/assist_satellite/icons.json
@@ -7,6 +7,9 @@
   "services": {
     "announce": {
       "service": "mdi:bullhorn"
+    },
+    "start_conversation": {
+      "service": "mdi:forum"
     }
   }
 }
diff --git a/homeassistant/components/assist_satellite/services.yaml b/homeassistant/components/assist_satellite/services.yaml
index e7fefc4705f..c6ebf81a225 100644
--- a/homeassistant/components/assist_satellite/services.yaml
+++ b/homeassistant/components/assist_satellite/services.yaml
@@ -14,3 +14,19 @@ announce:
       required: false
       selector:
         text:
+start_conversation:
+  target:
+    entity:
+      domain: assist_satellite
+      supported_features:
+        - assist_satellite.AssistSatelliteEntityFeature.START_CONVERSATION
+  fields:
+    start_message:
+      required: false
+      example: "You left the lights on in the living room. Turn them off?"
+      selector:
+        text:
+    start_media_id:
+      required: false
+      selector:
+        text:
diff --git a/homeassistant/components/assist_satellite/strings.json b/homeassistant/components/assist_satellite/strings.json
index 7f1426ef529..2e4a2855912 100644
--- a/homeassistant/components/assist_satellite/strings.json
+++ b/homeassistant/components/assist_satellite/strings.json
@@ -25,6 +25,20 @@
           "description": "The media ID to announce instead of using text-to-speech."
         }
       }
+    },
+    "start_conversation": {
+      "name": "Start Conversation",
+      "description": "Start a conversation from a satellite.",
+      "fields": {
+        "start_message": {
+          "name": "Message",
+          "description": "The message to start with."
+        },
+        "start_media_id": {
+          "name": "Media ID",
+          "description": "The media ID to start with instead of using text-to-speech."
+        }
+      }
     }
   }
 }
diff --git a/homeassistant/helpers/service.py b/homeassistant/helpers/service.py
index 255739c0059..4873d935537 100644
--- a/homeassistant/helpers/service.py
+++ b/homeassistant/helpers/service.py
@@ -88,6 +88,7 @@ def _base_components() -> dict[str, ModuleType]:
     # pylint: disable-next=import-outside-toplevel
     from homeassistant.components import (
         alarm_control_panel,
+        assist_satellite,
         calendar,
         camera,
         climate,
@@ -108,6 +109,7 @@ def _base_components() -> dict[str, ModuleType]:
 
     return {
         "alarm_control_panel": alarm_control_panel,
+        "assist_satellite": assist_satellite,
         "calendar": calendar,
         "camera": camera,
         "climate": climate,
diff --git a/tests/components/assist_satellite/conftest.py b/tests/components/assist_satellite/conftest.py
index d75cbd072e0..0cc0e94e149 100644
--- a/tests/components/assist_satellite/conftest.py
+++ b/tests/components/assist_satellite/conftest.py
@@ -40,6 +40,8 @@ def mock_tts(mock_tts_cache_dir: pathlib.Path) -> None:
 class MockAssistSatellite(AssistSatelliteEntity):
     """Mock Assist Satellite Entity."""
 
+    _attr_tts_options = {"test-option": "test-value"}
+
     def __init__(self, name: str, features: AssistSatelliteEntityFeature) -> None:
         """Initialize the mock entity."""
         self._attr_unique_id = ulid_hex()
@@ -67,6 +69,7 @@ class MockAssistSatellite(AssistSatelliteEntity):
             active_wake_words=["1234"],
             max_active_wake_words=1,
         )
+        self.start_conversations = []
 
     def on_pipeline_event(self, event: PipelineEvent) -> None:
         """Handle pipeline events."""
@@ -87,11 +90,21 @@ class MockAssistSatellite(AssistSatelliteEntity):
         """Set the current satellite configuration."""
         self.config = config
 
+    async def async_start_conversation(
+        self, start_announcement: AssistSatelliteConfiguration
+    ) -> None:
+        """Start a conversation from the satellite."""
+        self.start_conversations.append((self._extra_system_prompt, start_announcement))
+
 
 @pytest.fixture
 def entity() -> MockAssistSatellite:
     """Mock Assist Satellite Entity."""
-    return MockAssistSatellite("Test Entity", AssistSatelliteEntityFeature.ANNOUNCE)
+    return MockAssistSatellite(
+        "Test Entity",
+        AssistSatelliteEntityFeature.ANNOUNCE
+        | AssistSatelliteEntityFeature.START_CONVERSATION,
+    )
 
 
 @pytest.fixture
diff --git a/tests/components/assist_satellite/test_entity.py b/tests/components/assist_satellite/test_entity.py
index 0961c7dfbca..2a679642ffd 100644
--- a/tests/components/assist_satellite/test_entity.py
+++ b/tests/components/assist_satellite/test_entity.py
@@ -25,11 +25,24 @@ from homeassistant.components.assist_satellite.entity import AssistSatelliteStat
 from homeassistant.components.media_source import PlayMedia
 from homeassistant.config_entries import ConfigEntry
 from homeassistant.core import Context, HomeAssistant
+from homeassistant.exceptions import HomeAssistantError
 
 from . import ENTITY_ID
 from .conftest import MockAssistSatellite
 
 
+@pytest.fixture(autouse=True)
+async def set_pipeline_tts(hass: HomeAssistant, init_components: ConfigEntry) -> None:
+    """Set up a pipeline with a TTS engine."""
+    await async_update_pipeline(
+        hass,
+        async_get_pipeline(hass),
+        tts_engine="tts.mock_entity",
+        tts_language="en",
+        tts_voice="test-voice",
+    )
+
+
 async def test_entity_state(
     hass: HomeAssistant, init_components: ConfigEntry, entity: MockAssistSatellite
 ) -> None:
@@ -64,7 +77,7 @@ async def test_entity_state(
     assert kwargs["stt_stream"] is audio_stream
     assert kwargs["pipeline_id"] is None
     assert kwargs["device_id"] is entity.device_entry.id
-    assert kwargs["tts_audio_output"] is None
+    assert kwargs["tts_audio_output"] == {"test-option": "test-value"}
     assert kwargs["wake_word_phrase"] is None
     assert kwargs["audio_settings"] == AudioSettings(
         silence_seconds=vad.VadSensitivity.to_seconds(vad.VadSensitivity.DEFAULT)
@@ -189,24 +202,12 @@ async def test_announce(
     expected_params: tuple[str, str],
 ) -> None:
     """Test announcing on a device."""
-    await async_update_pipeline(
-        hass,
-        async_get_pipeline(hass),
-        tts_engine="tts.mock_entity",
-        tts_language="en",
-        tts_voice="test-voice",
-    )
-
-    entity._attr_tts_options = {"test-option": "test-value"}
-
     original_announce = entity.async_announce
-    announce_started = asyncio.Event()
 
     async def async_announce(announcement):
         # Verify state change
         assert entity.state == AssistSatelliteState.RESPONDING
         await original_announce(announcement)
-        announce_started.set()
 
     def tts_generate_media_source_id(
         hass: HomeAssistant,
@@ -464,3 +465,93 @@ async def test_vad_sensitivity_entity_not_found(
 
     with pytest.raises(RuntimeError):
         await entity.async_accept_pipeline_from_satellite(audio_stream)
+
+
+@pytest.mark.parametrize(
+    ("service_data", "expected_params"),
+    [
+        (
+            {
+                "start_message": "Hello",
+                "extra_system_prompt": "Better system prompt",
+            },
+            (
+                "Better system prompt",
+                AssistSatelliteAnnouncement(
+                    "Hello", "https://www.home-assistant.io/resolved.mp3", "tts"
+                ),
+            ),
+        ),
+        (
+            {
+                "start_message": "Hello",
+                "start_media_id": "media-source://bla",
+            },
+            (
+                "Hello",
+                AssistSatelliteAnnouncement(
+                    "Hello", "https://www.home-assistant.io/resolved.mp3", "media_id"
+                ),
+            ),
+        ),
+        (
+            {"start_media_id": "http://example.com/bla.mp3"},
+            (
+                None,
+                AssistSatelliteAnnouncement("", "http://example.com/bla.mp3", "url"),
+            ),
+        ),
+    ],
+)
+async def test_start_conversation(
+    hass: HomeAssistant,
+    init_components: ConfigEntry,
+    entity: MockAssistSatellite,
+    service_data: dict,
+    expected_params: tuple[str, str],
+) -> None:
+    """Test starting a conversation on a device."""
+    await async_update_pipeline(
+        hass,
+        async_get_pipeline(hass),
+        conversation_engine="conversation.some_llm",
+    )
+
+    with (
+        patch(
+            "homeassistant.components.assist_satellite.entity.tts_generate_media_source_id",
+            return_value="media-source://bla",
+        ),
+        patch(
+            "homeassistant.components.media_source.async_resolve_media",
+            return_value=PlayMedia(
+                url="https://www.home-assistant.io/resolved.mp3",
+                mime_type="audio/mp3",
+            ),
+        ),
+    ):
+        await hass.services.async_call(
+            "assist_satellite",
+            "start_conversation",
+            service_data,
+            target={"entity_id": "assist_satellite.test_entity"},
+            blocking=True,
+        )
+
+    assert entity.start_conversations[0] == expected_params
+
+
+async def test_start_conversation_reject_builtin_agent(
+    hass: HomeAssistant,
+    init_components: ConfigEntry,
+    entity: MockAssistSatellite,
+) -> None:
+    """Test starting a conversation on a device."""
+    with pytest.raises(HomeAssistantError):
+        await hass.services.async_call(
+            "assist_satellite",
+            "start_conversation",
+            {"start_message": "Hey!"},
+            target={"entity_id": "assist_satellite.test_entity"},
+            blocking=True,
+        )