diff --git a/README.md b/README.md
index fff4dae..98e56b2 100644
--- a/README.md
+++ b/README.md
@@ -40,7 +40,7 @@ For more details on ways to use the inspector, see the [Inspector section of the
 
 ### Authentication
 
-The inspector supports bearer token authentication for SSE connections. Enter your token in the UI when connecting to an MCP server, and it will be sent in the Authorization header.
+The inspector supports bearer token authentication for SSE connections. Enter your token in the UI when connecting to an MCP server, and it will be sent in the Authorization header. You can override the header name using the input field in the sidebar.
 
 ### Security Considerations
 
diff --git a/client/src/App.tsx b/client/src/App.tsx
index 04be204..5964bd8 100644
--- a/client/src/App.tsx
+++ b/client/src/App.tsx
@@ -117,6 +117,10 @@ const App = () => {
     return localStorage.getItem("lastBearerToken") || "";
   });
 
+  const [headerName, setHeaderName] = useState<string>(() => {
+    return localStorage.getItem("lastHeaderName") || "";
+  });
+
   const [pendingSampleRequests, setPendingSampleRequests] = useState<
     Array<
       PendingRequest & {
@@ -169,6 +173,7 @@ const App = () => {
     sseUrl,
     env,
     bearerToken,
+    headerName,
     config,
     onNotification: (notification) => {
       setNotifications((prev) => [...prev, notification as ServerNotification]);
@@ -208,6 +213,10 @@ const App = () => {
     localStorage.setItem("lastBearerToken", bearerToken);
   }, [bearerToken]);
 
+  useEffect(() => {
+    localStorage.setItem("lastHeaderName", headerName);
+  }, [headerName]);
+
   useEffect(() => {
     localStorage.setItem(CONFIG_LOCAL_STORAGE_KEY, JSON.stringify(config));
   }, [config]);
@@ -500,6 +509,8 @@ const App = () => {
         setConfig={setConfig}
         bearerToken={bearerToken}
         setBearerToken={setBearerToken}
+        headerName={headerName}
+        setHeaderName={setHeaderName}
         onConnect={connectMcpServer}
         onDisconnect={disconnectMcpServer}
         stdErrNotifications={stdErrNotifications}
diff --git a/client/src/components/Sidebar.tsx b/client/src/components/Sidebar.tsx
index efc054a..c736558 100644
--- a/client/src/components/Sidebar.tsx
+++ b/client/src/components/Sidebar.tsx
@@ -51,6 +51,8 @@ interface SidebarProps {
   setEnv: (env: Record<string, string>) => void;
   bearerToken: string;
   setBearerToken: (token: string) => void;
+  headerName?: string;
+  setHeaderName?: (name: string) => void;
   onConnect: () => void;
   onDisconnect: () => void;
   stdErrNotifications: StdErrNotification[];
@@ -76,6 +78,8 @@ const Sidebar = ({
   setEnv,
   bearerToken,
   setBearerToken,
+  headerName,
+  setHeaderName,
   onConnect,
   onDisconnect,
   stdErrNotifications,
@@ -176,6 +180,7 @@ const Sidebar = ({
                   variant="outline"
                   onClick={() => setShowBearerToken(!showBearerToken)}
                   className="flex items-center w-full"
+                  data-testid="auth-button"
                   aria-expanded={showBearerToken}
                 >
                   {showBearerToken ? (
@@ -187,6 +192,16 @@ const Sidebar = ({
                 </Button>
                 {showBearerToken && (
                   <div className="space-y-2">
+                    <label className="text-sm font-medium">Header Name</label>
+                    <Input
+                      placeholder="Authorization"
+                      onChange={(e) =>
+                        setHeaderName && setHeaderName(e.target.value)
+                      }
+                      data-testid="header-input"
+                      className="font-mono"
+                      value={headerName}
+                    />
                     <label
                       className="text-sm font-medium"
                       htmlFor="bearer-token-input"
@@ -198,6 +213,7 @@ const Sidebar = ({
                       placeholder="Bearer Token"
                       value={bearerToken}
                       onChange={(e) => setBearerToken(e.target.value)}
+                      data-testid="bearer-token-input"
                       className="font-mono"
                       type="password"
                     />
diff --git a/client/src/components/__tests__/Sidebar.test.tsx b/client/src/components/__tests__/Sidebar.test.tsx
index bce9737..980dc01 100644
--- a/client/src/components/__tests__/Sidebar.test.tsx
+++ b/client/src/components/__tests__/Sidebar.test.tsx
@@ -1,4 +1,5 @@
 import { render, screen, fireEvent } from "@testing-library/react";
+import "@testing-library/jest-dom";
 import { describe, it, beforeEach, jest } from "@jest/globals";
 import Sidebar from "../Sidebar";
 import { DEFAULT_INSPECTOR_CONFIG } from "@/lib/constants";
@@ -109,6 +110,157 @@ describe("Sidebar Environment Variables", () => {
     });
   });
 
+  describe("Authentication", () => {
+    const openAuthSection = () => {
+      const button = screen.getByTestId("auth-button");
+      fireEvent.click(button);
+    };
+
+    it("should update bearer token", () => {
+      const setBearerToken = jest.fn();
+      renderSidebar({
+        bearerToken: "",
+        setBearerToken,
+        transportType: "sse", // Set transport type to SSE
+      });
+
+      openAuthSection();
+
+      const tokenInput = screen.getByTestId("bearer-token-input");
+      fireEvent.change(tokenInput, { target: { value: "new_token" } });
+
+      expect(setBearerToken).toHaveBeenCalledWith("new_token");
+    });
+
+    it("should update header name", () => {
+      const setHeaderName = jest.fn();
+      renderSidebar({
+        headerName: "Authorization",
+        setHeaderName,
+        transportType: "sse",
+      });
+
+      openAuthSection();
+
+      const headerInput = screen.getByTestId("header-input");
+      fireEvent.change(headerInput, { target: { value: "X-Custom-Auth" } });
+
+      expect(setHeaderName).toHaveBeenCalledWith("X-Custom-Auth");
+    });
+
+    it("should clear bearer token", () => {
+      const setBearerToken = jest.fn();
+      renderSidebar({
+        bearerToken: "existing_token",
+        setBearerToken,
+        transportType: "sse", // Set transport type to SSE
+      });
+
+      openAuthSection();
+
+      const tokenInput = screen.getByTestId("bearer-token-input");
+      fireEvent.change(tokenInput, { target: { value: "" } });
+
+      expect(setBearerToken).toHaveBeenCalledWith("");
+    });
+
+    it("should properly render bearer token input", () => {
+      const { rerender } = renderSidebar({
+        bearerToken: "existing_token",
+        transportType: "sse", // Set transport type to SSE
+      });
+
+      openAuthSection();
+
+      // Token input should be a password field
+      const tokenInput = screen.getByTestId("bearer-token-input");
+      expect(tokenInput).toHaveProperty("type", "password");
+
+      // Update the token
+      fireEvent.change(tokenInput, { target: { value: "new_token" } });
+
+      // Rerender with updated token
+      rerender(
+        <TooltipProvider>
+          <Sidebar
+            {...defaultProps}
+            bearerToken="new_token"
+            transportType="sse"
+          />
+        </TooltipProvider>,
+      );
+
+      // Token input should still exist after update
+      expect(screen.getByTestId("bearer-token-input")).toBeInTheDocument();
+    });
+
+    it("should maintain token visibility state after update", () => {
+      const { rerender } = renderSidebar({
+        bearerToken: "existing_token",
+        transportType: "sse", // Set transport type to SSE
+      });
+
+      openAuthSection();
+
+      // Token input should be a password field
+      const tokenInput = screen.getByTestId("bearer-token-input");
+      expect(tokenInput).toHaveProperty("type", "password");
+
+      // Update the token
+      fireEvent.change(tokenInput, { target: { value: "new_token" } });
+
+      // Rerender with updated token
+      rerender(
+        <TooltipProvider>
+          <Sidebar
+            {...defaultProps}
+            bearerToken="new_token"
+            transportType="sse"
+          />
+        </TooltipProvider>,
+      );
+
+      // Token input should still exist after update
+      expect(screen.getByTestId("bearer-token-input")).toBeInTheDocument();
+    });
+
+    it("should maintain header name when toggling auth section", () => {
+      renderSidebar({
+        headerName: "X-API-Key",
+        transportType: "sse",
+      });
+
+      // Open auth section
+      openAuthSection();
+
+      // Verify header name is displayed
+      const headerInput = screen.getByTestId("header-input");
+      expect(headerInput).toHaveValue("X-API-Key");
+
+      // Close auth section
+      const authButton = screen.getByTestId("auth-button");
+      fireEvent.click(authButton);
+
+      // Reopen auth section
+      fireEvent.click(authButton);
+
+      // Verify header name is still preserved
+      expect(screen.getByTestId("header-input")).toHaveValue("X-API-Key");
+    });
+
+    it("should display default header name when not specified", () => {
+      renderSidebar({
+        headerName: undefined,
+        transportType: "sse",
+      });
+
+      openAuthSection();
+
+      const headerInput = screen.getByTestId("header-input");
+      expect(headerInput).toHaveAttribute("placeholder", "Authorization");
+    });
+  });
+
   describe("Key Editing", () => {
     it("should maintain order when editing first key", () => {
       const setEnv = jest.fn();
diff --git a/client/src/lib/hooks/useConnection.ts b/client/src/lib/hooks/useConnection.ts
index ac4605c..d5d7070 100644
--- a/client/src/lib/hooks/useConnection.ts
+++ b/client/src/lib/hooks/useConnection.ts
@@ -48,6 +48,7 @@ interface UseConnectionOptions {
   sseUrl: string;
   env: Record<string, string>;
   bearerToken?: string;
+  headerName?: string;
   config: InspectorConfig;
   onNotification?: (notification: Notification) => void;
   onStdErrNotification?: (notification: Notification) => void;
@@ -64,6 +65,7 @@ export function useConnection({
   sseUrl,
   env,
   bearerToken,
+  headerName,
   config,
   onNotification,
   onStdErrNotification,
@@ -293,7 +295,8 @@ export function useConnection({
       // Use manually provided bearer token if available, otherwise use OAuth tokens
       const token = bearerToken || (await authProvider.tokens())?.access_token;
       if (token) {
-        headers["Authorization"] = `Bearer ${token}`;
+        const authHeaderName = headerName || "Authorization";
+        headers[authHeaderName] = `Bearer ${token}`;
       }
 
       const clientTransport = new SSEClientTransport(mcpProxyServerUrl, {