diff --git a/src/components/layout/app-shell.tsx b/src/components/layout/app-shell.tsx
new file mode 100644
index 0000000..b18f0f4
--- /dev/null
+++ b/src/components/layout/app-shell.tsx
@@ -0,0 +1,18 @@
+import type { ReactNode } from "react";
+import { useLocation } from "react-router";
+import { Sidebar } from "./sidebar";
+
+interface AppShellProps {
+    children: ReactNode;
+}
+
+export const AppShell = ({ children }: AppShellProps) => {
+    const { pathname } = useLocation();
+
+    return (
+        <div className="flex min-h-screen bg-primary">
+            <Sidebar activeUrl={pathname} />
+            <main className="flex flex-1 flex-col overflow-auto">{children}</main>
+        </div>
+    );
+};
diff --git a/src/components/layout/sidebar.tsx b/src/components/layout/sidebar.tsx
new file mode 100644
index 0000000..a8cd367
--- /dev/null
+++ b/src/components/layout/sidebar.tsx
@@ -0,0 +1,126 @@
+import type { FC, HTMLAttributes } from "react";
+import { FontAwesomeIcon } from "@fortawesome/react-fontawesome";
+import {
+    faBullhorn,
+    faChartMixed,
+    faCommentDots,
+    faGear,
+    faGrid2,
+    faPlug,
+} from "@fortawesome/pro-regular-svg-icons";
+import { MobileNavigationHeader } from "@/components/application/app-navigation/base-components/mobile-header";
+import { NavAccountCard } from "@/components/application/app-navigation/base-components/nav-account-card";
+import { NavItemBase } from "@/components/application/app-navigation/base-components/nav-item";
+import type { NavItemType } from "@/components/application/app-navigation/config";
+
+// TODO: Wire to useAuth() once auth-provider.tsx is implemented
+const isAdmin = false;
+
+const MAIN_SIDEBAR_WIDTH = 292;
+
+// FontAwesome icon wrappers that satisfy FC<HTMLAttributes<HTMLOrSVGElement>>
+const IconGrid2: FC<HTMLAttributes<HTMLOrSVGElement>> = ({ className }) => (
+    <FontAwesomeIcon icon={faGrid2} className={className} />
+);
+const IconBullhorn: FC<HTMLAttributes<HTMLOrSVGElement>> = ({ className }) => (
+    <FontAwesomeIcon icon={faBullhorn} className={className} />
+);
+const IconCommentDots: FC<HTMLAttributes<HTMLOrSVGElement>> = ({ className }) => (
+    <FontAwesomeIcon icon={faCommentDots} className={className} />
+);
+const IconChartMixed: FC<HTMLAttributes<HTMLOrSVGElement>> = ({ className }) => (
+    <FontAwesomeIcon icon={faChartMixed} className={className} />
+);
+const IconPlug: FC<HTMLAttributes<HTMLOrSVGElement>> = ({ className }) => (
+    <FontAwesomeIcon icon={faPlug} className={className} />
+);
+const IconGear: FC<HTMLAttributes<HTMLOrSVGElement>> = ({ className }) => (
+    <FontAwesomeIcon icon={faGear} className={className} />
+);
+
+const mainItems: NavItemType[] = [
+    { label: "Lead Workspace", href: "/", icon: IconGrid2 },
+    { label: "Campaigns", href: "/campaigns", icon: IconBullhorn },
+    { label: "Outreach", href: "/outreach", icon: IconCommentDots },
+];
+
+const insightsItems: NavItemType[] = [
+    { label: "Analytics", href: "/analytics", icon: IconChartMixed },
+];
+
+const adminItems: NavItemType[] = [
+    { label: "Integrations", href: "/integrations", icon: IconPlug },
+    { label: "Settings", href: "/settings", icon: IconGear },
+];
+
+interface SidebarProps {
+    activeUrl?: string;
+}
+
+export const Sidebar = ({ activeUrl = "/" }: SidebarProps) => {
+    const navSections = [
+        { label: "Main", items: mainItems },
+        { label: "Insights", items: insightsItems },
+        ...(isAdmin ? [{ label: "Admin", items: adminItems }] : []),
+    ];
+
+    const content = (
+        <aside
+            style={{ "--width": `${MAIN_SIDEBAR_WIDTH}px` } as React.CSSProperties}
+            className="flex h-full w-full max-w-full flex-col justify-between overflow-auto border-secondary bg-primary pt-4 shadow-xs md:border-r lg:w-(--width) lg:rounded-xl lg:border lg:pt-5"
+        >
+            {/* Logo */}
+            <div className="flex flex-col gap-1 px-4 lg:px-5">
+                <span className="text-md font-bold text-primary">Helix Engage</span>
+                <span className="text-xs text-tertiary">Ramaiah Memorial Hospital</span>
+            </div>
+
+            {/* Nav sections */}
+            <ul className="mt-8">
+                {navSections.map((group) => (
+                    <li key={group.label}>
+                        <div className="px-5 pb-1">
+                            <p className="text-xs font-bold text-quaternary uppercase">{group.label}</p>
+                        </div>
+                        <ul className="px-4 pb-5">
+                            {group.items.map((item) => (
+                                <li key={item.label} className="py-0.5">
+                                    <NavItemBase
+                                        icon={item.icon}
+                                        href={item.href}
+                                        badge={item.badge}
+                                        type="link"
+                                        current={item.href === activeUrl}
+                                    >
+                                        {item.label}
+                                    </NavItemBase>
+                                </li>
+                            ))}
+                        </ul>
+                    </li>
+                ))}
+            </ul>
+
+            {/* Account card */}
+            <div className="mt-auto flex flex-col gap-5 px-2 py-4 lg:gap-6 lg:px-4 lg:py-4">
+                <NavAccountCard />
+            </div>
+        </aside>
+    );
+
+    return (
+        <>
+            {/* Mobile header navigation */}
+            <MobileNavigationHeader>{content}</MobileNavigationHeader>
+
+            {/* Desktop sidebar navigation */}
+            <div className="hidden lg:fixed lg:inset-y-0 lg:left-0 lg:flex lg:py-1 lg:pl-1">{content}</div>
+
+            {/* Placeholder to take up physical space because the real sidebar has `fixed` position. */}
+            <div
+                style={{ paddingLeft: MAIN_SIDEBAR_WIDTH + 4 }}
+                className="invisible hidden lg:sticky lg:top-0 lg:bottom-0 lg:left-0 lg:block"
+            />
+        </>
+    );
+};
diff --git a/src/components/layout/top-bar.tsx b/src/components/layout/top-bar.tsx
new file mode 100644
index 0000000..c833e36
--- /dev/null
+++ b/src/components/layout/top-bar.tsx
@@ -0,0 +1,30 @@
+import { SearchLg } from "@untitledui/icons";
+import { Avatar } from "@/components/base/avatar/avatar";
+import { Input } from "@/components/base/input/input";
+
+interface TopBarProps {
+    title: string;
+    subtitle?: string;
+}
+
+export const TopBar = ({ title, subtitle }: TopBarProps) => {
+    return (
+        <header className="flex h-16 items-center justify-between border-b border-secondary bg-primary px-6">
+            <div className="flex flex-col justify-center">
+                <h1 className="text-display-xs font-bold text-primary">{title}</h1>
+                {subtitle && <p className="text-sm text-tertiary">{subtitle}</p>}
+            </div>
+
+            <div className="flex items-center gap-3">
+                <div className="w-64">
+                    <Input
+                        placeholder="Search..."
+                        icon={SearchLg}
+                        aria-label="Search"
+                    />
+                </div>
+                <Avatar initials="SM" size="sm" />
+            </div>
+        </header>
+    );
+};
diff --git a/src/main.tsx b/src/main.tsx
index 947dae7..7cf1b00 100644
--- a/src/main.tsx
+++ b/src/main.tsx
@@ -1,8 +1,14 @@
 import { StrictMode } from "react";
 import { createRoot } from "react-dom/client";
-import { BrowserRouter, Route, Routes } from "react-router";
-import { HomeScreen } from "@/pages/home-screen";
+import { BrowserRouter, Outlet, Route, Routes } from "react-router";
+import { AppShell } from "@/components/layout/app-shell";
 import { NotFound } from "@/pages/not-found";
+import { AllLeadsPage } from "@/pages/all-leads";
+import { CampaignDetailPage } from "@/pages/campaign-detail";
+import { CampaignsPage } from "@/pages/campaigns";
+import { LeadWorkspacePage } from "@/pages/lead-workspace";
+import { LoginPage } from "@/pages/login";
+import { OutreachPage } from "@/pages/outreach";
 import { RouteProvider } from "@/providers/router-provider";
 import { ThemeProvider } from "@/providers/theme-provider";
 import "@/styles/globals.css";
@@ -13,8 +19,21 @@ createRoot(document.getElementById("root")!).render(
             <BrowserRouter>
                 <RouteProvider>
                     <Routes>
-                        <Route path="/" element={<HomeScreen />} />
-                        <Route path="*" element={<NotFound />} />
+                        <Route path="/login" element={<LoginPage />} />
+                        <Route
+                            element={
+                                <AppShell>
+                                    <Outlet />
+                                </AppShell>
+                            }
+                        >
+                            <Route path="/" element={<LeadWorkspacePage />} />
+                            <Route path="/leads" element={<AllLeadsPage />} />
+                            <Route path="/campaigns" element={<CampaignsPage />} />
+                            <Route path="/campaigns/:id" element={<CampaignDetailPage />} />
+                            <Route path="/outreach" element={<OutreachPage />} />
+                            <Route path="*" element={<NotFound />} />
+                        </Route>
                     </Routes>
                 </RouteProvider>
             </BrowserRouter>
diff --git a/src/pages/all-leads.tsx b/src/pages/all-leads.tsx
new file mode 100644
index 0000000..018d4f0
--- /dev/null
+++ b/src/pages/all-leads.tsx
@@ -0,0 +1,12 @@
+import { TopBar } from "@/components/layout/top-bar";
+
+export const AllLeadsPage = () => {
+    return (
+        <div className="flex flex-1 flex-col">
+            <TopBar title="All Leads" />
+            <div className="flex flex-1 items-center justify-center p-8">
+                <p className="text-tertiary">All Leads — coming soon</p>
+            </div>
+        </div>
+    );
+};
diff --git a/src/pages/campaign-detail.tsx b/src/pages/campaign-detail.tsx
new file mode 100644
index 0000000..f27804b
--- /dev/null
+++ b/src/pages/campaign-detail.tsx
@@ -0,0 +1,12 @@
+import { TopBar } from "@/components/layout/top-bar";
+
+export const CampaignDetailPage = () => {
+    return (
+        <div className="flex flex-1 flex-col">
+            <TopBar title="Campaign Detail" />
+            <div className="flex flex-1 items-center justify-center p-8">
+                <p className="text-tertiary">Campaign Detail — coming soon</p>
+            </div>
+        </div>
+    );
+};
diff --git a/src/pages/campaigns.tsx b/src/pages/campaigns.tsx
new file mode 100644
index 0000000..25c713f
--- /dev/null
+++ b/src/pages/campaigns.tsx
@@ -0,0 +1,12 @@
+import { TopBar } from "@/components/layout/top-bar";
+
+export const CampaignsPage = () => {
+    return (
+        <div className="flex flex-1 flex-col">
+            <TopBar title="Campaigns" />
+            <div className="flex flex-1 items-center justify-center p-8">
+                <p className="text-tertiary">Campaigns — coming soon</p>
+            </div>
+        </div>
+    );
+};
diff --git a/src/pages/lead-workspace.tsx b/src/pages/lead-workspace.tsx
new file mode 100644
index 0000000..cddaca5
--- /dev/null
+++ b/src/pages/lead-workspace.tsx
@@ -0,0 +1,12 @@
+import { TopBar } from "@/components/layout/top-bar";
+
+export const LeadWorkspacePage = () => {
+    return (
+        <div className="flex flex-1 flex-col">
+            <TopBar title="Lead Workspace" subtitle="Ramaiah Memorial Hospital · Last 24 hours" />
+            <div className="flex flex-1 items-center justify-center p-8">
+                <p className="text-tertiary">Lead Workspace — coming soon</p>
+            </div>
+        </div>
+    );
+};
diff --git a/src/pages/login.tsx b/src/pages/login.tsx
new file mode 100644
index 0000000..1222273
--- /dev/null
+++ b/src/pages/login.tsx
@@ -0,0 +1,3 @@
+export const LoginPage = () => {
+    return <div>Login placeholder</div>;
+};
diff --git a/src/pages/outreach.tsx b/src/pages/outreach.tsx
new file mode 100644
index 0000000..f52321f
--- /dev/null
+++ b/src/pages/outreach.tsx
@@ -0,0 +1,12 @@
+import { TopBar } from "@/components/layout/top-bar";
+
+export const OutreachPage = () => {
+    return (
+        <div className="flex flex-1 flex-col">
+            <TopBar title="Outreach" />
+            <div className="flex flex-1 items-center justify-center p-8">
+                <p className="text-tertiary">Outreach — coming soon</p>
+            </div>
+        </div>
+    );
+};