diff --git a/apps/web/src/App.tsx b/apps/web/src/App.tsx
index 3709ca9..94cc69c 100644
--- a/apps/web/src/App.tsx
+++ b/apps/web/src/App.tsx
@@ -8,6 +8,9 @@ import { LoginPage } from "./pages/LoginPage";
 import { RecipesPage } from "./pages/RecipesPage";
 import { ShoppingListPage } from "./pages/ShoppingListPage";
 import { SignupPage } from "./pages/SignupPage";
+import { OnboardingAllergensPage } from "./pages/onboarding/OnboardingAllergensPage";
+import { OnboardingDietPage } from "./pages/onboarding/OnboardingDietPage";
+import { OnboardingHouseholdPage } from "./pages/onboarding/OnboardingHouseholdPage";
 
 /**
  * Top-level route table. Every authenticated section is nested under one
@@ -16,6 +19,12 @@ import { SignupPage } from "./pages/SignupPage";
  * `/signup` redirect an already-logged-in visitor to `/` instead (see
  * {@link RedirectIfAuthenticated}). Anything else falls back to `/`, which
  * itself redirects to `/login` if needed.
+ *
+ * `/onboarding/*` (household/regime/allergens) is also `RequireAuth`-gated
+ * — reached right after signup, once a session already exists — but
+ * deliberately its own top-level route group, *not* nested under
+ * `AppLayout`: a focused, distraction-free wizard with no sidebar, same
+ * full-page-card language as `/login`/`/signup` (see `onboarding.scss`).
  */
 export function App() {
   return (
@@ -32,6 +41,30 @@ export function App() {
         <Route path="/liste-de-courses" element={<ShoppingListPage />} />
         <Route path="/foyer" element={<HouseholdPage />} />
       </Route>
+      <Route
+        path="/onboarding/foyer"
+        element={
+          <RequireAuth>
+            <OnboardingHouseholdPage />
+          </RequireAuth>
+        }
+      />
+      <Route
+        path="/onboarding/regime"
+        element={
+          <RequireAuth>
+            <OnboardingDietPage />
+          </RequireAuth>
+        }
+      />
+      <Route
+        path="/onboarding/allergenes"
+        element={
+          <RequireAuth>
+            <OnboardingAllergensPage />
+          </RequireAuth>
+        }
+      />
       <Route
         path="/login"
         element={
diff --git a/apps/web/src/features/auth/RedirectIfAuthenticated.tsx b/apps/web/src/features/auth/RedirectIfAuthenticated.tsx
index d4540b5..e20d8b4 100644
--- a/apps/web/src/features/auth/RedirectIfAuthenticated.tsx
+++ b/apps/web/src/features/auth/RedirectIfAuthenticated.tsx
@@ -1,4 +1,4 @@
-import type { ReactNode } from "react";
+import { type ReactNode, useRef } from "react";
 import { Navigate } from "react-router-dom";
 import { useAuth } from "./AuthContext";
 
@@ -6,14 +6,32 @@ import { useAuth } from "./AuthContext";
  * Route guard for pages that make no sense to an already-authenticated
  * visitor (`/login`, `/signup`). Mirrors {@link RequireAuth}'s waiting
  * behavior while the initial session check is pending.
+ *
+ * The redirect decision is latched exactly once, the first moment the
+ * initial `isLoading` check resolves — deliberately *not* reactive to
+ * `user` changing afterward. Without this, a guarded page's own action
+ * that authenticates the visitor (e.g. `SignupPage`'s submit handler
+ * calling `signup()`, which sets `user`, then explicitly navigating
+ * elsewhere) races this guard: `user` becoming truthy while still mounted
+ * fires this component's own `<Navigate to="/">`, competing with — and
+ * sometimes winning against — the page's explicit `navigate(...)` call to
+ * a different destination. Previously invisible only because the old
+ * `SignupPage` happened to navigate to the same place ("/") this guard
+ * does; became visible once it needed to route to `/onboarding/foyer`
+ * instead.
  */
 export function RedirectIfAuthenticated({ children }: { children: ReactNode }) {
   const { user, isLoading } = useAuth();
+  const shouldRedirect = useRef<boolean | null>(null);
 
-  if (isLoading) {
+  if (!isLoading && shouldRedirect.current === null) {
+    shouldRedirect.current = user !== null;
+  }
+
+  if (isLoading || shouldRedirect.current === null) {
     return null;
   }
-  if (user) {
+  if (shouldRedirect.current) {
     return <Navigate to="/" replace />;
   }
   return <>{children}</>;
diff --git a/apps/web/src/locales/fr/translation.json b/apps/web/src/locales/fr/translation.json
index 22894db..0bd77e8 100644
--- a/apps/web/src/locales/fr/translation.json
+++ b/apps/web/src/locales/fr/translation.json
@@ -32,6 +32,21 @@
       "loginLink": "Se connecter"
     }
   },
+  "onboarding": {
+    "step": "Étape {{current}} sur {{total}}",
+    "continue": "Continuer",
+    "finish": "Terminer",
+    "loading": "Chargement…",
+    "household": {
+      "title": "Comment s'appelle votre foyer ?"
+    },
+    "diet": {
+      "title": "Un régime alimentaire particulier ?"
+    },
+    "allergens": {
+      "title": "Des allergies ou intolérances ?"
+    }
+  },
   "layout": {
     "nav": {
       "planning": "Planning",
diff --git a/apps/web/src/pages/SignupPage.tsx b/apps/web/src/pages/SignupPage.tsx
index 662d839..56260ba 100644
--- a/apps/web/src/pages/SignupPage.tsx
+++ b/apps/web/src/pages/SignupPage.tsx
@@ -37,7 +37,7 @@ export function SignupPage() {
   const [formError, setFormError] = useState<string | null>(null);
   const [isSubmitting, setIsSubmitting] = useState(false);
 
-  /** Validates, then submits the form; navigates home on success. */
+  /** Validates, then submits the form; on success, starts the household/regime/allergens onboarding wizard rather than going straight to the home. */
   async function handleSubmit(e: FormEvent) {
     e.preventDefault();
     setFormError(null);
@@ -52,7 +52,7 @@ export function SignupPage() {
     setIsSubmitting(true);
     try {
       await signup(result.data);
-      navigate("/");
+      navigate("/onboarding/foyer");
     } catch (err) {
       // ApiError.code is looked up through ErrorMessageService so the
       // label is centralized and localized — never display err.message
diff --git a/apps/web/src/pages/onboarding/OnboardingAllergensPage.tsx b/apps/web/src/pages/onboarding/OnboardingAllergensPage.tsx
new file mode 100644
index 0000000..ff433a2
--- /dev/null
+++ b/apps/web/src/pages/onboarding/OnboardingAllergensPage.tsx
@@ -0,0 +1,80 @@
+import type { AllergyView } from "@batch-cooking/shared";
+import { ErrorCode } from "@batch-cooking/shared";
+import { type FormEvent, useEffect, useState } from "react";
+import { useTranslation } from "react-i18next";
+import { useNavigate } from "react-router-dom";
+import { ApiError, apiClient } from "../../api/client";
+import { AllergySelect } from "../../features/profile/AllergySelect";
+import { errorMessageService } from "../../services/error-message.service";
+import "./onboarding.scss";
+
+/**
+ * Last step of the post-signup onboarding wizard, routed at
+ * `/onboarding/allergenes`. Starts from an empty selection — a freshly
+ * signed-up profile has none yet, so there's no need for the extra
+ * `GET /profile/allergies` round trip a "resume where I left off" flow
+ * would require (the `/foyer` settings page, task 10, is the always-fetch
+ * source of truth for editing an existing selection later).
+ */
+export function OnboardingAllergensPage() {
+  const { t } = useTranslation();
+  const navigate = useNavigate();
+
+  const [allergies, setAllergies] = useState<AllergyView[]>([]);
+  const [allergyIds, setAllergyIds] = useState<number[]>([]);
+  const [isLoading, setIsLoading] = useState(true);
+  const [formError, setFormError] = useState<string | null>(null);
+  const [isSubmitting, setIsSubmitting] = useState(false);
+
+  useEffect(() => {
+    let cancelled = false;
+    apiClient
+      .getAllergies()
+      .then((result) => {
+        if (!cancelled) setAllergies(result);
+      })
+      .finally(() => {
+        if (!cancelled) setIsLoading(false);
+      });
+    return () => {
+      cancelled = true;
+    };
+  }, []);
+
+  /** Finishes the wizard — the profile journey is complete, back to the app itself. */
+  async function handleSubmit(e: FormEvent) {
+    e.preventDefault();
+    setFormError(null);
+    setIsSubmitting(true);
+    try {
+      await apiClient.updateAllergyIds(allergyIds);
+      navigate("/");
+    } catch (err) {
+      const code = err instanceof ApiError ? err.code : ErrorCode.INTERNAL_ERROR;
+      setFormError(errorMessageService.getLabel(code));
+    } finally {
+      setIsSubmitting(false);
+    }
+  }
+
+  return (
+    <main className="onboarding-page">
+      <form className="onboarding-card" onSubmit={handleSubmit} noValidate>
+        <p className="onboarding-step">{t("onboarding.step", { current: 3, total: 3 })}</p>
+        <h1>{t("onboarding.allergens.title")}</h1>
+
+        {isLoading ? (
+          <p>{t("onboarding.loading")}</p>
+        ) : (
+          <AllergySelect allergies={allergies} value={allergyIds} onChange={setAllergyIds} />
+        )}
+
+        {formError && <p className="form-error">{formError}</p>}
+
+        <button type="submit" disabled={isSubmitting || isLoading}>
+          {t("onboarding.finish")}
+        </button>
+      </form>
+    </main>
+  );
+}
diff --git a/apps/web/src/pages/onboarding/OnboardingDietPage.tsx b/apps/web/src/pages/onboarding/OnboardingDietPage.tsx
new file mode 100644
index 0000000..a29fef9
--- /dev/null
+++ b/apps/web/src/pages/onboarding/OnboardingDietPage.tsx
@@ -0,0 +1,80 @@
+import type { DietView } from "@batch-cooking/shared";
+import { ErrorCode } from "@batch-cooking/shared";
+import { type FormEvent, useEffect, useState } from "react";
+import { useTranslation } from "react-i18next";
+import { useNavigate } from "react-router-dom";
+import { ApiError, apiClient } from "../../api/client";
+import { useAuth } from "../../features/auth/AuthContext";
+import { DietSelect } from "../../features/profile/DietSelect";
+import { errorMessageService } from "../../services/error-message.service";
+import "./onboarding.scss";
+
+/**
+ * Second step of the post-signup onboarding wizard, routed at
+ * `/onboarding/regime`. Initial selection comes from `useAuth()`'s
+ * already-loaded profile (`user.dietId`) — freshly signed-up, this is
+ * `null` — no extra fetch needed just to know the starting value, unlike
+ * the household step which has no such shortcut for the current name.
+ */
+export function OnboardingDietPage() {
+  const { t } = useTranslation();
+  const navigate = useNavigate();
+  const { user } = useAuth();
+
+  const [diets, setDiets] = useState<DietView[]>([]);
+  const [dietId, setDietId] = useState<number | null>(user?.dietId ?? null);
+  const [isLoading, setIsLoading] = useState(true);
+  const [formError, setFormError] = useState<string | null>(null);
+  const [isSubmitting, setIsSubmitting] = useState(false);
+
+  useEffect(() => {
+    let cancelled = false;
+    apiClient
+      .getDiets()
+      .then((result) => {
+        if (!cancelled) setDiets(result);
+      })
+      .finally(() => {
+        if (!cancelled) setIsLoading(false);
+      });
+    return () => {
+      cancelled = true;
+    };
+  }, []);
+
+  async function handleSubmit(e: FormEvent) {
+    e.preventDefault();
+    setFormError(null);
+    setIsSubmitting(true);
+    try {
+      await apiClient.updateDiet(dietId);
+      navigate("/onboarding/allergenes");
+    } catch (err) {
+      const code = err instanceof ApiError ? err.code : ErrorCode.INTERNAL_ERROR;
+      setFormError(errorMessageService.getLabel(code));
+    } finally {
+      setIsSubmitting(false);
+    }
+  }
+
+  return (
+    <main className="onboarding-page">
+      <form className="onboarding-card" onSubmit={handleSubmit} noValidate>
+        <p className="onboarding-step">{t("onboarding.step", { current: 2, total: 3 })}</p>
+        <h1>{t("onboarding.diet.title")}</h1>
+
+        {isLoading ? (
+          <p>{t("onboarding.loading")}</p>
+        ) : (
+          <DietSelect diets={diets} value={dietId} onChange={setDietId} />
+        )}
+
+        {formError && <p className="form-error">{formError}</p>}
+
+        <button type="submit" disabled={isSubmitting || isLoading}>
+          {t("onboarding.continue")}
+        </button>
+      </form>
+    </main>
+  );
+}
diff --git a/apps/web/src/pages/onboarding/OnboardingHouseholdPage.tsx b/apps/web/src/pages/onboarding/OnboardingHouseholdPage.tsx
new file mode 100644
index 0000000..eef0d85
--- /dev/null
+++ b/apps/web/src/pages/onboarding/OnboardingHouseholdPage.tsx
@@ -0,0 +1,88 @@
+import { ErrorCode, renameHouseSchema } from "@batch-cooking/shared";
+import { type FormEvent, useEffect, useState } from "react";
+import { useTranslation } from "react-i18next";
+import { useNavigate } from "react-router-dom";
+import { ApiError, apiClient } from "../../api/client";
+import { HouseNameField } from "../../features/profile/HouseNameField";
+import { fieldErrorsFrom } from "../../lib/zod-errors";
+import { errorMessageService } from "../../services/error-message.service";
+import "./onboarding.scss";
+
+/**
+ * First step of the post-signup onboarding wizard, routed at
+ * `/onboarding/foyer` — behind {@link RequireAuth} (see `App.tsx`), reached
+ * right after `POST /auth/signup` creates the account and its household
+ * (auto-named, see `auth.service.ts`). Prefills the current (default) name
+ * so continuing without editing it is a valid, implicit "skip" — there's
+ * no separate skip button anywhere in this wizard, see `DietSelect`/
+ * `AllergySelect` for the same choice on the following steps.
+ */
+export function OnboardingHouseholdPage() {
+  const { t } = useTranslation();
+  const navigate = useNavigate();
+
+  const [name, setName] = useState("");
+  const [isLoading, setIsLoading] = useState(true);
+  const [fieldErrors, setFieldErrors] = useState<Record<string, string>>({});
+  const [formError, setFormError] = useState<string | null>(null);
+  const [isSubmitting, setIsSubmitting] = useState(false);
+
+  useEffect(() => {
+    let cancelled = false;
+    apiClient
+      .getCurrentHouse()
+      .then((house) => {
+        if (!cancelled && house) setName(house.name);
+      })
+      .finally(() => {
+        if (!cancelled) setIsLoading(false);
+      });
+    return () => {
+      cancelled = true;
+    };
+  }, []);
+
+  async function handleSubmit(e: FormEvent) {
+    e.preventDefault();
+    setFormError(null);
+
+    const result = renameHouseSchema.safeParse({ name });
+    if (!result.success) {
+      setFieldErrors(fieldErrorsFrom(result.error));
+      return;
+    }
+    setFieldErrors({});
+
+    setIsSubmitting(true);
+    try {
+      await apiClient.renameHouse(result.data.name);
+      navigate("/onboarding/regime");
+    } catch (err) {
+      const code = err instanceof ApiError ? err.code : ErrorCode.INTERNAL_ERROR;
+      setFormError(errorMessageService.getLabel(code));
+    } finally {
+      setIsSubmitting(false);
+    }
+  }
+
+  return (
+    <main className="onboarding-page">
+      <form className="onboarding-card" onSubmit={handleSubmit} noValidate>
+        <p className="onboarding-step">{t("onboarding.step", { current: 1, total: 3 })}</p>
+        <h1>{t("onboarding.household.title")}</h1>
+
+        {isLoading ? (
+          <p>{t("onboarding.loading")}</p>
+        ) : (
+          <HouseNameField value={name} onChange={setName} error={fieldErrors.name} />
+        )}
+
+        {formError && <p className="form-error">{formError}</p>}
+
+        <button type="submit" disabled={isSubmitting || isLoading}>
+          {t("onboarding.continue")}
+        </button>
+      </form>
+    </main>
+  );
+}
diff --git a/apps/web/src/pages/onboarding/onboarding.scss b/apps/web/src/pages/onboarding/onboarding.scss
new file mode 100644
index 0000000..379c8eb
--- /dev/null
+++ b/apps/web/src/pages/onboarding/onboarding.scss
@@ -0,0 +1,74 @@
+// =============================================================================
+// Styles shared by the three onboarding wizard pages (OnboardingHousehold,
+// OnboardingDiet, OnboardingAllergens) — the household/regime/allergens
+// steps of the profile journey, run once right after signup.
+//
+// Deliberately its own file rather than importing features/auth/
+// auth-form.scss: same visual language (centered card) but a different
+// feature area — matches the project's existing convention of colocating
+// styles per feature rather than sharing a "global card" partial (see
+// HomePage.scss, which makes the same call for its own button styling).
+// =============================================================================
+
+.onboarding-page {
+  min-height: 100vh;
+  display: flex;
+  align-items: center;
+  justify-content: center;
+  padding: var(--space-md);
+  background: var(--color-background);
+}
+
+.onboarding-card {
+  display: flex;
+  flex-direction: column;
+  gap: var(--space-xs);
+  width: 100%;
+  max-width: var(--max-width-form);
+  padding: var(--space-xl);
+  background: var(--color-surface);
+  border-radius: var(--radius-md);
+  box-shadow: var(--shadow-md);
+
+  h1 {
+    font-size: var(--font-size-lg);
+    text-align: center;
+    margin-bottom: var(--space-sm);
+  }
+
+  button {
+    margin-top: var(--space-md);
+    padding: 0.6rem;
+    font-family: var(--font-body);
+    font-size: var(--font-size-base);
+    font-weight: 600;
+    cursor: pointer;
+    border-radius: var(--radius-base);
+    border: none;
+    background: var(--color-primary);
+    color: #fff;
+
+    &:hover:not(:disabled) {
+      background: var(--color-primary-hover);
+    }
+
+    &:disabled {
+      opacity: 0.6;
+      cursor: not-allowed;
+    }
+  }
+}
+
+.onboarding-step {
+  color: var(--color-text-muted);
+  font-size: var(--font-size-xs);
+  text-align: center;
+  text-transform: uppercase;
+  letter-spacing: 0.04em;
+  margin: 0 0 var(--space-sm);
+}
+
+.form-error {
+  color: var(--color-error);
+  font-size: var(--font-size-sm);
+}