diff --git a/src/app/chat/page.tsx b/src/app/chat/page.tsx
index 97efc60..2e04dcb 100644
--- a/src/app/chat/page.tsx
+++ b/src/app/chat/page.tsx
@@ -4954,6 +4954,7 @@ export default function ChatPage() {
                     companyId={company?.id}
                     sessionKey={activeThread.sessionKey}
                     realtimeRuntimeId={selectedAgent?.runtimeId ?? undefined}
+                    voiceSettings={resolvedVoiceSettings}
                   />
                 </div>
               ) : null}
@@ -5962,6 +5963,7 @@ export default function ChatPage() {
                     ? selectedSessionKey ?? gatewaySessionKeyForAgent(selectedAgent)
                     : gatewaySessionKeyForAgent(selectedAgent)}
                   realtimeRuntimeId={selectedAgent?.runtimeId ?? undefined}
+                  voiceSettings={resolvedVoiceSettings}
                 />
                 <div className={agentOverlayMode === "immersive"
                   ? "absolute right-4 top-[max(var(--mobile-safe-top),1rem)] z-10 flex gap-2 sm:right-6"
diff --git a/src/components/chat/voice-agent.tsx b/src/components/chat/voice-agent.tsx
index 9359b0e..0324e1f 100644
--- a/src/components/chat/voice-agent.tsx
+++ b/src/components/chat/voice-agent.tsx
@@ -23,8 +23,13 @@ import {
   startNativeVoiceSession,
   stopNativeVoiceSession,
 } from "@/lib/native-voice-session";
-import { startRealtimeVoiceSession, type RealtimeVoiceSession } from "@/lib/realtime-voice-client";
+import {
+  resolveRealtimeVoiceSessionSettings,
+  startRealtimeVoiceSession,
+  type RealtimeVoiceSession,
+} from "@/lib/realtime-voice-client";
 import { RealtimeGatewayRelaySession, type RealtimeVoiceStatus } from "@/lib/realtime-voice-gateway-relay";
+import type { AgentVoiceSettings } from "@/lib/tts-voices";
 
 type AgentState = "listening" | "processing" | "speaking" | "muted" | "idle";
 
@@ -54,6 +59,7 @@ interface VoiceAgentProps {
   companyId?: string;
   sessionKey?: string;
   realtimeRuntimeId?: string;
+  voiceSettings?: AgentVoiceSettings | null;
 }
 
 function hexToRgb(hex: string): string {
@@ -118,6 +124,7 @@ export function VoiceAgent({
   companyId,
   sessionKey,
   realtimeRuntimeId,
+  voiceSettings,
 }: VoiceAgentProps) {
   const [state, setState] = useState<AgentState>("idle");
   const [isActive, setIsActive] = useState(false);
@@ -466,16 +473,21 @@ export function VoiceAgent({
     if (!realtimeEnabled || !realtimeRuntimeId) return false;
 
     try {
+      const realtimeVoiceSettings = resolveRealtimeVoiceSessionSettings(voiceSettings);
       const session = await startRealtimeVoiceSession({
         runtimeId: realtimeRuntimeId,
         sessionKey,
         agentId: gatewayAgent ?? agent,
+        ...realtimeVoiceSettings,
       });
       setRealtimeSession(session);
       recordVoiceBreadcrumb("realtime.session.start", {
         transport: session.transport,
         provider: session.provider,
         model: session.model,
+        requestedProvider: realtimeVoiceSettings.provider,
+        requestedVoice: realtimeVoiceSettings.voice,
+        requestedModel: realtimeVoiceSettings.model,
         hasRelaySessionId: Boolean(session.relaySessionId),
       });
       publishAgentModeDiagnostic({
@@ -486,6 +498,9 @@ export function VoiceAgent({
           transport: session.transport,
           provider: session.provider,
           model: session.model,
+          requestedProvider: realtimeVoiceSettings.provider,
+          requestedVoice: realtimeVoiceSettings.voice,
+          requestedModel: realtimeVoiceSettings.model,
           hasRelaySessionId: Boolean(session.relaySessionId),
         },
       });
@@ -540,7 +555,7 @@ export function VoiceAgent({
       });
       return false;
     }
-  }, [agent, gatewayAgent, onRealtimeTranscript, realtimeEnabled, realtimeRuntimeId, recordVoiceBreadcrumb, requestWakeLock, sessionKey]);
+  }, [agent, gatewayAgent, onRealtimeTranscript, realtimeEnabled, realtimeRuntimeId, recordVoiceBreadcrumb, requestWakeLock, sessionKey, voiceSettings]);
 
   const activate = useCallback(async () => {
     onMicMutedChange?.(false);
diff --git a/src/lib/realtime-voice-client.test.ts b/src/lib/realtime-voice-client.test.ts
index 1ecda75..c7f8d95 100644
--- a/src/lib/realtime-voice-client.test.ts
+++ b/src/lib/realtime-voice-client.test.ts
@@ -2,6 +2,7 @@ import { beforeEach, describe, expect, it, vi } from "vitest";
 import {
   cancelRealtimeRelayOutput,
   openRealtimeRelayEvents,
+  resolveRealtimeVoiceSessionSettings,
   sendRealtimeRelayAudio,
   sendRealtimeRelayToolCall,
   startRealtimeVoiceSession,
@@ -116,4 +117,35 @@ describe("realtime voice client helpers", () => {
       "/api/runtimes/rt_1/talk/realtime/events?relaySessionId=relay+1",
     );
   });
+
+  it("maps OpenAI voice selections to realtime session settings", () => {
+    expect(resolveRealtimeVoiceSessionSettings({
+      enabled: true,
+      provider: "openai",
+      voiceId: "cedar",
+      model: "gpt-realtime-1.5",
+    })).toEqual({
+      provider: "openai",
+      voice: "cedar",
+      model: "gpt-realtime-1.5",
+    });
+  });
+
+  it("does not forward non-realtime TTS voice settings", () => {
+    expect(resolveRealtimeVoiceSessionSettings({
+      enabled: true,
+      provider: "elevenlabs",
+      voiceId: "eleven_voice",
+    })).toEqual({});
+    expect(resolveRealtimeVoiceSessionSettings({
+      enabled: true,
+      provider: "openai",
+      voiceId: "onyx",
+      model: "tts-1",
+    })).toEqual({
+      provider: "openai",
+      voice: undefined,
+      model: undefined,
+    });
+  });
 });
diff --git a/src/lib/realtime-voice-client.ts b/src/lib/realtime-voice-client.ts
index e9f2715..86bff65 100644
--- a/src/lib/realtime-voice-client.ts
+++ b/src/lib/realtime-voice-client.ts
@@ -1,5 +1,20 @@
+import { normalizeAgentVoiceSettings, type AgentVoiceSettings } from "@/lib/tts-voices";
+
 export type RealtimeVoiceTransport = "webrtc-sdp" | "json-pcm-websocket" | "gateway-relay";
 
+const OPENAI_REALTIME_VOICE_IDS = new Set([
+  "alloy",
+  "ash",
+  "ballad",
+  "cedar",
+  "coral",
+  "echo",
+  "marin",
+  "sage",
+  "shimmer",
+  "verse",
+]);
+
 export interface RealtimeVoiceSessionRequest {
   runtimeId: string;
   sessionKey?: string;
@@ -80,6 +95,21 @@ export async function startRealtimeVoiceSession(
   };
 }
 
+export function resolveRealtimeVoiceSessionSettings(
+  voiceSettings?: AgentVoiceSettings | null,
+): Pick<RealtimeVoiceSessionRequest, "provider" | "model" | "voice"> {
+  const voice = normalizeAgentVoiceSettings(voiceSettings);
+  if (voice.enabled === false || voice.provider !== "openai") return {};
+
+  const voiceId = voice.voiceId?.trim().toLowerCase();
+  const model = voice.model?.trim();
+  return {
+    provider: "openai",
+    voice: voiceId && OPENAI_REALTIME_VOICE_IDS.has(voiceId) ? voiceId : undefined,
+    model: model?.includes("realtime") ? model : undefined,
+  };
+}
+
 export async function sendRealtimeRelayAudio(runtimeId: string, chunk: RealtimeRelayAudioChunk): Promise<void> {
   await postRealtimeRelay(runtimeId, {
     action: "audio",