diff --git a/backend/main.py b/backend/main.py
index e33ce59a6..43e608da4 100644
--- a/backend/main.py
+++ b/backend/main.py
@@ -62,6 +62,13 @@ async def list_conversations():
     return storage.list_conversations()
 
 
+@app.delete("/api/conversations")
+async def delete_conversations():
+    """Delete all conversations from storage."""
+    storage.delete_all_conversations()
+    return {"status": "ok"}
+
+
 @app.post("/api/conversations", response_model=Conversation)
 async def create_conversation(request: CreateConversationRequest):
     """Create a new conversation."""
diff --git a/backend/storage.py b/backend/storage.py
index 180111da4..b017b571c 100644
--- a/backend/storage.py
+++ b/backend/storage.py
@@ -170,3 +170,18 @@ def update_conversation_title(conversation_id: str, title: str):
 
     conversation["title"] = title
     save_conversation(conversation)
+
+
+def delete_all_conversations():
+    """
+    Delete all conversation files from the data directory.
+    """
+    ensure_data_dir()
+    for filename in os.listdir(DATA_DIR):
+        if filename.endswith('.json'):
+            path = os.path.join(DATA_DIR, filename)
+            try:
+                os.remove(path)
+            except OSError:
+                # ignore failures to remove individual files
+                pass
diff --git a/frontend/src/App.jsx b/frontend/src/App.jsx
index 195415598..559277bb8 100644
--- a/frontend/src/App.jsx
+++ b/frontend/src/App.jsx
@@ -53,6 +53,18 @@ function App() {
     }
   };
 
+  const handleClearConversations = async () => {
+    if (!window.confirm('Clear all conversations? This cannot be undone.')) return;
+    try {
+      await api.deleteAllConversations();
+      setConversations([]);
+      setCurrentConversationId(null);
+      setCurrentConversation(null);
+    } catch (error) {
+      console.error('Failed to clear conversations:', error);
+    }
+  };
+
   const handleSelectConversation = (id) => {
     setCurrentConversationId(id);
   };
@@ -188,6 +200,7 @@ function App() {
         currentConversationId={currentConversationId}
         onSelectConversation={handleSelectConversation}
         onNewConversation={handleNewConversation}
+        onClearConversations={handleClearConversations}
       />
       <ChatInterface
         conversation={currentConversation}
diff --git a/frontend/src/api.js b/frontend/src/api.js
index 87ec685ba..98666cb82 100644
--- a/frontend/src/api.js
+++ b/frontend/src/api.js
@@ -112,4 +112,17 @@ export const api = {
       }
     }
   },
+  
+  /**
+   * Delete all conversations from the backend.
+   */
+  async deleteAllConversations() {
+    const response = await fetch(`${API_BASE}/api/conversations`, {
+      method: 'DELETE',
+    });
+    if (!response.ok) {
+      throw new Error('Failed to delete conversations');
+    }
+    return response.json();
+  },
 };
diff --git a/frontend/src/components/Sidebar.css b/frontend/src/components/Sidebar.css
index c4f4b97b2..d423ffa50 100644
--- a/frontend/src/components/Sidebar.css
+++ b/frontend/src/components/Sidebar.css
@@ -36,6 +36,22 @@
   border-color: #357abd;
 }
 
+.clear-history-btn {
+  width: 100%;
+  margin-top: 8px;
+  padding: 8px;
+  background: #fff;
+  border: 1px solid #d9534f;
+  color: #d9534f;
+  border-radius: 6px;
+  cursor: pointer;
+  font-size: 13px;
+}
+
+.clear-history-btn:hover {
+  background: #fcebea;
+}
+
 .conversation-list {
   flex: 1;
   overflow-y: auto;
diff --git a/frontend/src/components/Sidebar.jsx b/frontend/src/components/Sidebar.jsx
index 1376f4e99..3a356cced 100644
--- a/frontend/src/components/Sidebar.jsx
+++ b/frontend/src/components/Sidebar.jsx
@@ -6,6 +6,7 @@ export default function Sidebar({
   currentConversationId,
   onSelectConversation,
   onNewConversation,
+  onClearConversations,
 }) {
   return (
     <div className="sidebar">
@@ -14,6 +15,14 @@ export default function Sidebar({
         <button className="new-conversation-btn" onClick={onNewConversation}>
           + New Conversation
         </button>
+        <button
+          className="clear-history-btn"
+          onClick={() => {
+            if (typeof onClearConversations === 'function') onClearConversations();
+          }}
+        >
+          Clear History
+        </button>
       </div>
 
       <div className="conversation-list">