diff --git a/homeassistant/components/ollama/entity.py b/homeassistant/components/ollama/entity.py
index 2581698e185..95ddcc402c0 100644
--- a/homeassistant/components/ollama/entity.py
+++ b/homeassistant/components/ollama/entity.py
@@ -95,6 +95,7 @@ def _convert_content(
         return ollama.Message(
             role=MessageRole.ASSISTANT.value,
             content=chat_content.content,
+            thinking=chat_content.thinking_content,
             tool_calls=[
                 ollama.Message.ToolCall(
                     function=ollama.Message.ToolCall.Function(
@@ -103,7 +104,8 @@ def _convert_content(
                     )
                 )
                 for tool_call in chat_content.tool_calls or ()
-            ],
+            ]
+            or None,
         )
     if isinstance(chat_content, conversation.UserContent):
         images: list[ollama.Image] = []
@@ -162,6 +164,8 @@ async def _transform_stream(
             ]
         if (content := response_message.get("content")) is not None:
             chunk["content"] = content
+        if (thinking := response_message.get("thinking")) is not None:
+            chunk["thinking_content"] = thinking
         if response_message.get("done"):
             new_msg = True
         yield chunk
diff --git a/tests/components/ollama/test_conversation.py b/tests/components/ollama/test_conversation.py
index 4904829a31c..4e5ddf286ba 100644
--- a/tests/components/ollama/test_conversation.py
+++ b/tests/components/ollama/test_conversation.py
@@ -145,6 +145,70 @@ async def test_chat_stream(
         assert result.response.speech["plain"]["speech"] == "test response"
 
 
+async def test_thinking_content(
+    hass: HomeAssistant,
+    mock_config_entry: MockConfigEntry,
+    mock_init_component,
+) -> None:
+    """Test that thinking content is retained in multi-turn conversation."""
+
+    entry = MockConfigEntry()
+    entry.add_to_hass(hass)
+
+    subentry = next(iter(mock_config_entry.subentries.values()))
+    hass.config_entries.async_update_subentry(
+        mock_config_entry,
+        subentry,
+        data={
+            **subentry.data,
+            ollama.CONF_THINK: True,
+        },
+    )
+
+    conversation_id = "conversation_id_1234"
+
+    with patch(
+        "ollama.AsyncClient.chat",
+        return_value=stream_generator(
+            {
+                "message": {
+                    "role": "assistant",
+                    "content": "test response",
+                    "thinking": "test thinking",
+                },
+                "done": True,
+                "done_reason": "stop",
+            },
+        ),
+    ) as mock_chat:
+        await conversation.async_converse(
+            hass,
+            "test message",
+            conversation_id,
+            Context(),
+            agent_id=mock_config_entry.entry_id,
+        )
+
+        await conversation.async_converse(
+            hass,
+            "test message 2",
+            conversation_id,
+            Context(),
+            agent_id=mock_config_entry.entry_id,
+        )
+
+        assert mock_chat.call_count == 2
+        assert mock_chat.call_args.kwargs["messages"][1:] == [
+            Message(role="user", content="test message"),
+            Message(
+                role="assistant",
+                content="test response",
+                thinking="test thinking",
+            ),
+            Message(role="user", content="test message 2"),
+        ]
+
+
 async def test_template_variables(
     hass: HomeAssistant, mock_config_entry: MockConfigEntry
 ) -> None: