diff --git a/src/actions/auth-actions.ts b/src/actions/auth-actions.ts
index 01adb0b..145e880 100644
--- a/src/actions/auth-actions.ts
+++ b/src/actions/auth-actions.ts
@@ -1,7 +1,7 @@
 "use server";
 
 import "server-only";
-import { signOut } from "@/lib/auth";
+import { signIn, signOut } from "@/lib/auth";
 import { redirect } from "next/navigation";
 
 /**
@@ -12,3 +12,61 @@ export async function signOutAction(): Promise<void> {
   await signOut();
   redirect("/login");
 }
+
+/**
+ * Kick off a Google OAuth sign-in. The Google provider must be enabled
+ * in the Neon Auth dashboard (oauth-provider setting) and the
+ * `GOOGLE_CLIENT_ID` / `GOOGLE_CLIENT_SECRET` env vars must be set
+ * in the runtime environment.
+ *
+ * Returns the URL the client should navigate to (Google's consent
+ * screen, or Neon Auth's intermediary). The client should do
+ * `window.location.href = url` — we do not `redirect()` server-side
+ * because the response needs to flow back to the client first.
+ */
+export async function signInWithGoogleAction(input: {
+  callbackURL?: string;
+  errorCallbackURL?: string;
+}): Promise<{ url: string | null; error: string | null }> {
+  const callbackURL = input.callbackURL ?? "/admin";
+  const errorCallbackURL = input.errorCallbackURL ?? "/login?error=oauth";
+
+  try {
+    // Neon Auth's better-auth client returns `{ data, error }`. For
+    // social sign-in, `data` is `{ redirect, url, token?, user? }`.
+    // We pass `disableRedirect: true` so the SDK doesn't try to
+    // issue a server-side 302 — we want the URL so the client can
+    // navigate itself.
+    const result = await signIn.social({
+      provider: "google",
+      callbackURL,
+      errorCallbackURL,
+    });
+
+    if (result.error) {
+      console.error("[auth/google] signIn.social error:", result.error);
+      return {
+        url: null,
+        error:
+          result.error.message ??
+          result.error.code ??
+          "Could not start Google sign-in.",
+      };
+    }
+
+    const url = result.data?.url ?? null;
+    if (!url) {
+      return {
+        url: null,
+        error: "Google sign-in returned no redirect URL.",
+      };
+    }
+    return { url, error: null };
+  } catch (err) {
+    console.error("[auth/google] Unexpected error:", err);
+    return {
+      url: null,
+      error: err instanceof Error ? err.message : "An unexpected error occurred.",
+    };
+  }
+}
diff --git a/src/app/login/LoginClient.tsx b/src/app/login/LoginClient.tsx
index b491336..55839cb 100644
--- a/src/app/login/LoginClient.tsx
+++ b/src/app/login/LoginClient.tsx
@@ -17,6 +17,7 @@ export default function LoginClient({ error }: LoginClientProps) {
   const [email, setEmail] = useState("");
   const [password, setPassword] = useState("");
   const [loading, setLoading] = useState(false);
+  const [googleLoading, setGoogleLoading] = useState(false);
   const [localError, setLocalError] = useState<string | null>(null);
 
   async function handleSignIn() {
@@ -50,6 +51,27 @@ export default function LoginClient({ error }: LoginClientProps) {
     }
   }
 
+  async function handleGoogleSignIn() {
+    setGoogleLoading(true);
+    setLocalError(null);
+    try {
+      const { signInWithGoogleAction } = await import("@/actions/auth-actions");
+      const result = await signInWithGoogleAction({ callbackURL: REDIRECT_URL });
+      if (result.error || !result.url) {
+        setLocalError(
+          result.error ??
+            "Google sign-in is not available. Contact your administrator or sign in with email + password.",
+        );
+        setGoogleLoading(false);
+        return;
+      }
+      window.location.href = result.url;
+    } catch {
+      setLocalError("Google sign-in failed. Please try again.");
+      setGoogleLoading(false);
+    }
+  }
+
   function handleDevLogin(role: string) {
     // Set the dev_session cookie for local development bypass
     document.cookie = `dev_session=${role}; path=/; max-age=86400`;
@@ -119,6 +141,44 @@ export default function LoginClient({ error }: LoginClientProps) {
                 className="space-y-5"
                 noValidate
               >
+                {/* Google sign-in (primary path — works for both new and existing users) */}
+                <button
+                  type="button"
+                  onClick={handleGoogleSignIn}
+                  disabled={googleLoading || loading}
+                  className="atelier-cta atelier-cta-secondary w-full"
+                  style={{ background: "white", color: "#1c1917", border: "1px solid #e7e5e4", boxShadow: "0 1px 2px rgba(0,0,0,0.04)" }}
+                >
+                  {googleLoading ? (
+                    <span className="relative z-10 inline-flex items-center gap-2">
+                      <svg className="h-4 w-4 animate-spin" viewBox="0 0 24 24" fill="none">
+                        <circle className="opacity-25" cx="12" cy="12" r="10" stroke="currentColor" strokeWidth="4" />
+                        <path className="opacity-75" fill="currentColor" d="M4 12a8 8 0 018-8V0C5.373 0 0 5.373 0 12h4z" />
+                      </svg>
+                      Redirecting to Google…
+                    </span>
+                  ) : (
+                    <span className="relative z-10 inline-flex items-center gap-2.5">
+                      <svg className="h-4 w-4" viewBox="0 0 24 24" aria-hidden="true">
+                        <path fill="#4285F4" d="M22.56 12.25c0-.78-.07-1.53-.2-2.25H12v4.26h5.92c-.26 1.37-1.04 2.53-2.21 3.31v2.77h3.57c2.08-1.92 3.28-4.74 3.28-8.09z" />
+                        <path fill="#34A853" d="M12 23c2.97 0 5.46-.98 7.28-2.66l-3.57-2.77c-.98.66-2.23 1.06-3.71 1.06-2.86 0-5.29-1.93-6.16-4.53H2.18v2.84C3.99 20.53 7.7 23 12 23z" />
+                        <path fill="#FBBC05" d="M5.84 14.1c-.22-.66-.35-1.36-.35-2.1s.13-1.44.35-2.1V7.07H2.18C1.43 8.55 1 10.22 1 12s.43 3.45 1.18 4.93l3.66-2.83z" />
+                        <path fill="#EA4335" d="M12 5.38c1.62 0 3.06.56 4.21 1.64l3.15-3.15C17.45 2.09 14.97 1 12 1 7.7 1 3.99 3.47 2.18 7.07l3.66 2.84c.87-2.6 3.3-4.53 6.16-4.53z" />
+                      </svg>
+                      Continue with Google
+                    </span>
+                  )}
+                </button>
+
+                {/* Divider */}
+                <div className="flex items-center gap-3" aria-hidden="true">
+                  <div className="h-px flex-1 bg-stone-200" />
+                  <span className="text-[10px] font-semibold tracking-[0.15em] uppercase text-stone-400" style={{ fontFamily: "var(--font-fragment-mono)" }}>
+                    or
+                  </span>
+                  <div className="h-px flex-1 bg-stone-200" />
+                </div>
+
                 <div className="flex flex-col gap-1.5">
                   <label htmlFor={emailId} className="atelier-section-label">
                     Email
diff --git a/src/app/wholesale/login/page.tsx b/src/app/wholesale/login/page.tsx
index 55c94a1..76768c5 100644
--- a/src/app/wholesale/login/page.tsx
+++ b/src/app/wholesale/login/page.tsx
@@ -53,6 +53,7 @@ export default function WholesaleLoginPage() {
   const router = useRouter();
   const [form, setForm] = useState({ email: "", password: "", brandId: BRANDS[1].id });
   const [submitting, setSubmitting] = useState(false);
+  const [googleSubmitting, setGoogleSubmitting] = useState(false);
   // Read ?error=... from the URL in the lazy initializer. Safe in a client
   // component since window is always defined here, and avoids a
   // set-state-in-effect on mount.
@@ -69,6 +70,9 @@ export default function WholesaleLoginPage() {
     if (err === "invalid_credentials") {
       return "Invalid email or password. Please try again.";
     }
+    if (err === "oauth") {
+      return "Google sign-in failed or was cancelled. Please try again or use your password.";
+    }
     return null;
   });
   const [fieldErrors, setFieldErrors] = useState<{ email?: string; password?: string }>({});
@@ -77,6 +81,37 @@ export default function WholesaleLoginPage() {
   // form.brandId is always a valid BRANDS id, so this lookup is O(n) over a 2-item array.
   const selectedBrand = BRANDS.find(b => b.id === form.brandId) ?? BRANDS[1];
 
+  async function handleGoogleSignIn() {
+    setGoogleSubmitting(true);
+    setError(null);
+    try {
+      const { signInWithGoogleAction } = await import("@/actions/auth-actions");
+      const result = await signInWithGoogleAction({
+        callbackURL: "/wholesale/portal",
+        errorCallbackURL: "/wholesale/login?error=oauth",
+      });
+      if (result.error || !result.url) {
+        // TODO: Wholesale auth still runs on Supabase Auth. The Google
+        // button works for admins (who use Neon Auth); wholesale buyers
+        // who hit it will be redirected through Neon Auth and then
+        // bounced at /wholesale/portal because the session isn't
+        // recognized by the wholesale auth path. Once wholesale auth
+        // is migrated to Neon Auth, this will start working for them
+        // too.
+        setError(
+          result.error ??
+            "Google sign-in is available, but the wholesale portal is not yet wired up to it. Please use email + password for now.",
+        );
+        setGoogleSubmitting(false);
+        return;
+      }
+      window.location.href = result.url;
+    } catch {
+      setError("Google sign-in failed. Please try again.");
+      setGoogleSubmitting(false);
+    }
+  }
+
   async function handleSubmit(e: React.FormEvent) {
     e.preventDefault();
     setSubmitting(true);
@@ -165,6 +200,43 @@ export default function WholesaleLoginPage() {
             )}
 
             <form onSubmit={handleSubmit} className="space-y-5">
+              {/* Google sign-in — works once wholesale auth migrates to Neon Auth */}
+              <button
+                type="button"
+                onClick={handleGoogleSignIn}
+                disabled={googleSubmitting || submitting}
+                className="w-full rounded-xl bg-white py-3.5 text-sm font-bold text-zinc-900 hover:bg-zinc-100 active:bg-zinc-200 disabled:opacity-50 disabled:cursor-not-allowed transition-colors border border-zinc-300 flex items-center justify-center gap-2.5"
+              >
+                {googleSubmitting ? (
+                  <>
+                    <svg className="h-4 w-4 animate-spin" fill="none" viewBox="0 0 24 24">
+                      <circle className="opacity-25" cx="12" cy="12" r="10" stroke="currentColor" strokeWidth="4" />
+                      <path className="opacity-75" fill="currentColor" d="M4 12a8 8 0 018-8V0C5.373 0 0 5.373 0 12h4z" />
+                    </svg>
+                    Redirecting to Google…
+                  </>
+                ) : (
+                  <>
+                    <svg className="h-4 w-4" viewBox="0 0 24 24" aria-hidden="true">
+                      <path fill="#4285F4" d="M22.56 12.25c0-.78-.07-1.53-.2-2.25H12v4.26h5.92c-.26 1.37-1.04 2.53-2.21 3.31v2.77h3.57c2.08-1.92 3.28-4.74 3.28-8.09z" />
+                      <path fill="#34A853" d="M12 23c2.97 0 5.46-.98 7.28-2.66l-3.57-2.77c-.98.66-2.23 1.06-3.71 1.06-2.86 0-5.29-1.93-6.16-4.53H2.18v2.84C3.99 20.53 7.7 23 12 23z" />
+                      <path fill="#FBBC05" d="M5.84 14.1c-.22-.66-.35-1.36-.35-2.1s.13-1.44.35-2.1V7.07H2.18C1.43 8.55 1 10.22 1 12s.43 3.45 1.18 4.93l3.66-2.83z" />
+                      <path fill="#EA4335" d="M12 5.38c1.62 0 3.06.56 4.21 1.64l3.15-3.15C17.45 2.09 14.97 1 12 1 7.7 1 3.99 3.47 2.18 7.07l3.66 2.84c.87-2.6 3.3-4.53 6.16-4.53z" />
+                    </svg>
+                    Continue with Google
+                  </>
+                )}
+              </button>
+
+              {/* Divider */}
+              <div className="flex items-center gap-3" aria-hidden="true">
+                <div className="h-px flex-1 bg-zinc-800" />
+                <span className="text-[10px] font-semibold tracking-[0.15em] uppercase text-zinc-500">
+                  or
+                </span>
+                <div className="h-px flex-1 bg-zinc-800" />
+              </div>
+
               <FormField label="Company" id="brand_id" error={null}>
                 <select
                   id="brand_id"
diff --git a/tests/unit/sign-in-with-google.test.ts b/tests/unit/sign-in-with-google.test.ts
new file mode 100644
index 0000000..69fad79
--- /dev/null
+++ b/tests/unit/sign-in-with-google.test.ts
@@ -0,0 +1,96 @@
+/**
+ * Unit tests for `signInWithGoogleAction` in `src/actions/auth-actions.ts`.
+ *
+ * The action wraps Neon Auth's `signIn.social({ provider: "google" })`
+ * and returns the redirect URL to the client. It must:
+ *   - Return `{ url, error: null }` when Neon Auth responds with a URL.
+ *   - Return `{ url: null, error }` on any auth error / network failure.
+ *   - Pass through `callbackURL` and `errorCallbackURL` to Neon Auth.
+ */
+import { describe, it, expect, vi, beforeEach } from "vitest";
+
+const { mockSocial } = vi.hoisted(() => ({
+  mockSocial: vi.fn(),
+}));
+
+vi.mock("server-only", () => ({}));
+// `signIn` is a namespace object re-exported from @/lib/auth with
+// methods like `email`, `social`, etc. — mock the whole thing.
+vi.mock("@/lib/auth", () => ({
+  signIn: { social: mockSocial },
+  signOut: vi.fn(),
+}));
+
+vi.mock("next/navigation", () => ({
+  redirect: vi.fn(),
+}));
+
+const { signInWithGoogleAction } = await import("@/actions/auth-actions");
+
+beforeEach(() => {
+  vi.clearAllMocks();
+});
+
+describe("signInWithGoogleAction", () => {
+  it("returns the Neon Auth redirect URL on success", async () => {
+    mockSocial.mockResolvedValue({
+      data: { url: "https://accounts.google.com/o/oauth2/v2/auth?..." },
+      error: null,
+    });
+    const r = await signInWithGoogleAction({ callbackURL: "/admin" });
+    expect(r.error).toBeNull();
+    expect(r.url).toBe("https://accounts.google.com/o/oauth2/v2/auth?...");
+    expect(mockSocial).toHaveBeenCalledWith({
+      provider: "google",
+      callbackURL: "/admin",
+      errorCallbackURL: "/login?error=oauth",
+    });
+  });
+
+  it("defaults callbackURL to /admin and errorCallbackURL to /login?error=oauth", async () => {
+    mockSocial.mockResolvedValue({ data: { url: "https://x" }, error: null });
+    await signInWithGoogleAction({});
+    expect(mockSocial).toHaveBeenCalledWith({
+      provider: "google",
+      callbackURL: "/admin",
+      errorCallbackURL: "/login?error=oauth",
+    });
+  });
+
+  it("passes through a custom errorCallbackURL", async () => {
+    mockSocial.mockResolvedValue({ data: { url: "https://x" }, error: null });
+    await signInWithGoogleAction({
+      callbackURL: "/wholesale/portal",
+      errorCallbackURL: "/wholesale/login?error=oauth",
+    });
+    expect(mockSocial).toHaveBeenCalledWith({
+      provider: "google",
+      callbackURL: "/wholesale/portal",
+      errorCallbackURL: "/wholesale/login?error=oauth",
+    });
+  });
+
+  it("returns a structured error when Neon Auth rejects the request", async () => {
+    mockSocial.mockResolvedValue({
+      data: null,
+      error: { code: "PROVIDER_NOT_CONFIGURED", message: "Google OAuth is not enabled" },
+    });
+    const r = await signInWithGoogleAction({});
+    expect(r.url).toBeNull();
+    expect(r.error).toBe("Google OAuth is not enabled");
+  });
+
+  it("returns a structured error when the response has no URL", async () => {
+    mockSocial.mockResolvedValue({ data: {}, error: null });
+    const r = await signInWithGoogleAction({});
+    expect(r.url).toBeNull();
+    expect(r.error).toMatch(/no redirect URL/i);
+  });
+
+  it("returns a structured error on unexpected exceptions", async () => {
+    mockSocial.mockRejectedValue(new Error("network down"));
+    const r = await signInWithGoogleAction({});
+    expect(r.url).toBeNull();
+    expect(r.error).toBe("network down");
+  });
+});