diff --git a/src/__tests__/PageInjections.test.tsx b/src/__tests__/PageInjections.test.tsx
new file mode 100644
index 0000000..c28136d
--- /dev/null
+++ b/src/__tests__/PageInjections.test.tsx
@@ -0,0 +1,142 @@
+import { describe, expect, it } from "vitest";
+import type { ArgoCDApplication } from "../api/argocd";
+
+// --- Matching helpers (copied for unit testing) ---
+
+function appsForNamespace(
+  apps: ArgoCDApplication[],
+  namespace: string
+): ArgoCDApplication[] {
+  return apps.filter((app) => app.spec?.destination?.namespace === namespace);
+}
+
+function appsForDeployment(
+  apps: ArgoCDApplication[],
+  deploymentName: string
+): ArgoCDApplication[] {
+  return apps.filter((app) =>
+    (app.status?.resources ?? []).some(
+      (res) => res.kind === "Deployment" && res.name === deploymentName
+    )
+  );
+}
+
+// --- Fixture factory ---
+
+function makeApp(
+  overrides: Partial<ArgoCDApplication> = {}
+): ArgoCDApplication {
+  return {
+    metadata: { name: "test-app", namespace: "argocd" },
+    spec: { project: "default" },
+    status: {},
+    ...overrides,
+  } as ArgoCDApplication;
+}
+
+// --- appsForNamespace tests ---
+
+describe("appsForNamespace", () => {
+  it("returns apps whose destination.namespace matches", () => {
+    const apps = [
+      makeApp({
+        metadata: { name: "app-a", namespace: "argocd" },
+        spec: { project: "default", destination: { namespace: "web" } },
+      }),
+      makeApp({
+        metadata: { name: "app-b", namespace: "argocd" },
+        spec: { project: "default", destination: { namespace: "data" } },
+      }),
+    ];
+    expect(appsForNamespace(apps, "web").map((a) => a.metadata.name)).toEqual([
+      "app-a",
+    ]);
+  });
+
+  it("returns empty array when no match", () => {
+    const apps = [
+      makeApp({
+        metadata: { name: "app-a", namespace: "argocd" },
+        spec: { project: "default", destination: { namespace: "web" } },
+      }),
+    ];
+    expect(appsForNamespace(apps, "data")).toEqual([]);
+  });
+
+  it("returns empty array for empty app list", () => {
+    expect(appsForNamespace([], "web")).toEqual([]);
+  });
+
+  it("returns empty array when destination is undefined", () => {
+    const apps = [
+      makeApp({
+        metadata: { name: "app-a", namespace: "argocd" },
+        spec: { project: "default" },
+      }),
+    ];
+    expect(appsForNamespace(apps, "web")).toEqual([]);
+  });
+});
+
+// --- appsForDeployment tests ---
+
+describe("appsForDeployment", () => {
+  it("returns apps that manage the deployment via status.resources", () => {
+    const apps = [
+      makeApp({
+        metadata: { name: "app-a", namespace: "argocd" },
+        status: {
+          resources: [{ kind: "Deployment", name: "nginx", namespace: "web" }],
+        },
+      }),
+      makeApp({
+        metadata: { name: "app-b", namespace: "argocd" },
+        status: {
+          resources: [{ kind: "Service", name: "nginx", namespace: "web" }],
+        },
+      }),
+    ];
+    expect(
+      appsForDeployment(apps, "nginx").map((a) => a.metadata.name)
+    ).toEqual(["app-a"]);
+  });
+
+  it("returns empty array when no deployment resource matches", () => {
+    const apps = [
+      makeApp({
+        metadata: { name: "app-a", namespace: "argocd" },
+        status: {
+          resources: [{ kind: "Service", name: "nginx", namespace: "web" }],
+        },
+      }),
+    ];
+    expect(appsForDeployment(apps, "nginx")).toEqual([]);
+  });
+
+  it("returns empty array for empty app list", () => {
+    expect(appsForDeployment([], "nginx")).toEqual([]);
+  });
+
+  it("returns empty array when resources is undefined", () => {
+    const apps = [
+      makeApp({ metadata: { name: "app-a", namespace: "argocd" }, status: {} }),
+    ];
+    expect(appsForDeployment(apps, "nginx")).toEqual([]);
+  });
+
+  it("returns multiple apps that manage the same deployment", () => {
+    const apps = [
+      makeApp({
+        metadata: { name: "app-a", namespace: "argocd" },
+        status: { resources: [{ kind: "Deployment", name: "nginx" }] },
+      }),
+      makeApp({
+        metadata: { name: "app-b", namespace: "argocd" },
+        status: { resources: [{ kind: "Deployment", name: "nginx" }] },
+      }),
+    ];
+    expect(
+      appsForDeployment(apps, "nginx").map((a) => a.metadata.name)
+    ).toEqual(["app-a", "app-b"]);
+  });
+});
diff --git a/src/components/DeploymentArgoBadge.tsx b/src/components/DeploymentArgoBadge.tsx
new file mode 100644
index 0000000..878d6b7
--- /dev/null
+++ b/src/components/DeploymentArgoBadge.tsx
@@ -0,0 +1,101 @@
+import { ApiProxy } from "@kinvolk/headlamp-plugin/lib";
+import {
+  Link,
+  StatusLabel,
+} from "@kinvolk/headlamp-plugin/lib/CommonComponents";
+import React, { useEffect, useState } from "react";
+import { ArgoCDApplication, ArgoCDApplicationsList } from "../api/argocd";
+import { syncStatusToColor } from "./ApplicationsList";
+
+// --- API ---
+
+const ARGOCD_API_PATH =
+  "/api/v1/namespaces/argocd/services/argocd-server/proxy/api/v1/applications";
+
+async function fetchApplications(): Promise<ArgoCDApplicationsList> {
+  const response = (await ApiProxy.request(
+    ARGOCD_API_PATH
+  )) as ArgoCDApplicationsList;
+  return response;
+}
+
+// --- Matching helper ---
+
+/**
+ * Returns ArgoCD applications that manage the given Deployment by matching
+ * kind=Deployment and name in Application.status.resources[].
+ */
+export function appsForDeployment(
+  apps: ArgoCDApplication[],
+  deploymentName: string
+): ArgoCDApplication[] {
+  return apps.filter((app) =>
+    (app.status?.resources ?? []).some(
+      (res) => res.kind === "Deployment" && res.name === deploymentName
+    )
+  );
+}
+
+// --- Component ---
+
+interface DeploymentArgoBadgeProps {
+  deploymentName: string;
+}
+
+export default function DeploymentArgoBadge({
+  deploymentName,
+}: DeploymentArgoBadgeProps) {
+  const [apps, setApps] = useState<ArgoCDApplication[] | null>(null);
+  const [loading, setLoading] = useState(true);
+  const [error, setError] = useState<string | null>(null);
+
+  useEffect(() => {
+    let cancelled = false;
+    fetchApplications()
+      .then((data) => {
+        if (cancelled) return;
+        const matched = appsForDeployment(data.items ?? [], deploymentName);
+        setApps(matched);
+        setLoading(false);
+      })
+      .catch((err: unknown) => {
+        if (cancelled) return;
+        setError(err instanceof Error ? err.message : String(err));
+        setLoading(false);
+      });
+    return () => {
+      cancelled = true;
+    };
+  }, [deploymentName]);
+
+  if (loading || error || !apps || apps.length === 0) {
+    return null; // Show nothing when no matching application
+  }
+
+  const app = apps[0]; // Show first matching app
+  const lastSynced = app.status?.history?.length
+    ? app.status.history[app.status.history.length - 1]?.dexKey
+    : null;
+  const lastSyncedStr = lastSynced
+    ? new Date(lastSynced).toLocaleString()
+    : "—";
+
+  return (
+    <span>
+      &nbsp;
+      <Link to={`/argocd/applications/${app.metadata.name}`}>
+        ArgoCD: {app.metadata.name}
+      </Link>
+      &nbsp;
+      <StatusLabel
+        status={syncStatusToColor(app.status?.sync?.status ?? "Unknown")}
+      >
+        {app.status?.sync?.status ?? "Unknown"}
+      </StatusLabel>
+      &nbsp;
+      <span style={{ fontSize: "0.85em", opacity: 0.8 }}>
+        Last sync: {lastSyncedStr}
+      </span>
+    </span>
+  );
+}
diff --git a/src/components/NamespaceArgoSection.tsx b/src/components/NamespaceArgoSection.tsx
new file mode 100644
index 0000000..8679729
--- /dev/null
+++ b/src/components/NamespaceArgoSection.tsx
@@ -0,0 +1,120 @@
+import { ApiProxy } from "@kinvolk/headlamp-plugin/lib";
+import {
+  Link,
+  SectionBox,
+  StatusLabel,
+} from "@kinvolk/headlamp-plugin/lib/CommonComponents";
+import React, { useEffect, useState } from "react";
+import { ArgoCDApplication, ArgoCDApplicationsList } from "../api/argocd";
+import {
+  healthStatusToColor,
+  healthStatusToLabel,
+  syncStatusToColor,
+} from "./ApplicationsList";
+
+// --- API ---
+
+const ARGOCD_API_PATH =
+  "/api/v1/namespaces/argocd/services/argocd-server/proxy/api/v1/applications";
+
+async function fetchApplications(): Promise<ArgoCDApplicationsList> {
+  const response = (await ApiProxy.request(
+    ARGOCD_API_PATH
+  )) as ArgoCDApplicationsList;
+  return response;
+}
+
+// --- Matching helper ---
+
+/**
+ * Returns ArgoCD applications whose spec.destination.namespace matches
+ * the given namespace name.
+ */
+export function appsForNamespace(
+  apps: ArgoCDApplication[],
+  namespace: string
+): ArgoCDApplication[] {
+  return apps.filter((app) => app.spec?.destination?.namespace === namespace);
+}
+
+// --- Component ---
+
+interface NamespaceArgoSectionProps {
+  namespaceName: string;
+}
+
+export default function NamespaceArgoSection({
+  namespaceName,
+}: NamespaceArgoSectionProps) {
+  const [apps, setApps] = useState<ArgoCDApplication[] | null>(null);
+  const [loading, setLoading] = useState(true);
+  const [error, setError] = useState<string | null>(null);
+
+  useEffect(() => {
+    let cancelled = false;
+    fetchApplications()
+      .then((data) => {
+        if (cancelled) return;
+        const matched = appsForNamespace(data.items ?? [], namespaceName);
+        setApps(matched);
+        setLoading(false);
+      })
+      .catch((err: unknown) => {
+        if (cancelled) return;
+        setError(err instanceof Error ? err.message : String(err));
+        setLoading(false);
+      });
+    return () => {
+      cancelled = true;
+    };
+  }, [namespaceName]);
+
+  if (loading) {
+    return (
+      <SectionBox title="ArgoCD">
+        <StatusLabel status="warning">Loading...</StatusLabel>
+      </SectionBox>
+    );
+  }
+
+  if (error || !apps) {
+    return (
+      <SectionBox title="ArgoCD">
+        <StatusLabel status="error">ArgoCD unreachable</StatusLabel>
+      </SectionBox>
+    );
+  }
+
+  if (apps.length === 0) {
+    return null; // Show nothing when no matching application
+  }
+
+  return (
+    <SectionBox title="ArgoCD">
+      <StatusLabel status="success">{apps.length} application(s)</StatusLabel>
+      <ul style={{ paddingLeft: 20, margin: "8px 0" }}>
+        {apps.map((app) => (
+          <li key={app.metadata.name} style={{ marginBottom: 8 }}>
+            <Link to={`/argocd/applications/${app.metadata.name}`}>
+              {app.metadata.name}
+            </Link>
+            &nbsp;
+            <StatusLabel
+              status={healthStatusToColor(
+                app.status?.health?.status ?? "Unknown"
+              )}
+            >
+              {healthStatusToLabel(app.status?.health?.status ?? "Unknown")}
+            </StatusLabel>
+            &nbsp;
+            <StatusLabel
+              status={syncStatusToColor(app.status?.sync?.status ?? "Unknown")}
+            >
+              {app.status?.sync?.status ?? "Unknown"}
+            </StatusLabel>
+          </li>
+        ))}
+      </ul>
+    </SectionBox>
+  );
+}
diff --git a/src/components/PageInjections.tsx b/src/components/PageInjections.tsx
new file mode 100644
index 0000000..bbd8bdb
--- /dev/null
+++ b/src/components/PageInjections.tsx
@@ -0,0 +1,207 @@
+/**
+ * Page injection registrations for ArgoCD plugin.
+ * Registers detail view sections on Namespace and Deployment pages.
+ */
+import { ApiProxy } from "@kinvolk/headlamp-plugin/lib";
+import { KubeObject } from "@kinvolk/headlamp-plugin/lib/lib/k8s/KubeObject";
+import { registerDetailsViewSection } from "@kinvolk/headlamp-plugin/lib";
+import {
+  SectionBox,
+  StatusLabel,
+} from "@kinvolk/headlamp-plugin/lib/CommonComponents";
+import { Link } from "react-router-dom";
+import React, { useEffect, useState } from "react";
+import { ArgoCDApplication, ArgoCDApplicationsList } from "../api/argocd";
+import {
+  healthStatusToColor,
+  healthStatusToLabel,
+  syncStatusToColor,
+} from "./ApplicationsList";
+
+// --- API ---
+
+const ARGOCD_API_PATH =
+  "/api/v1/namespaces/argocd/services/argocd-server/proxy/api/v1/applications";
+
+async function fetchApplications(): Promise<ArgoCDApplicationsList> {
+  const response = (await ApiProxy.request(
+    ARGOCD_API_PATH
+  )) as ArgoCDApplicationsList;
+  return response;
+}
+
+// --- Namespace section ---
+
+function NamespaceArgoSection({ resource }: { resource: KubeObject }) {
+  const namespaceName = resource.metadata.name;
+  const [apps, setApps] = useState<ArgoCDApplication[] | null>(null);
+  const [loading, setLoading] = useState(true);
+  const [error, setError] = useState<string | null>(null);
+
+  useEffect(() => {
+    let cancelled = false;
+    fetchApplications()
+      .then((data) => {
+        if (cancelled) return;
+        const matched = (data.items ?? []).filter(
+          (app) => app.spec?.destination?.namespace === namespaceName
+        );
+        setApps(matched);
+        setLoading(false);
+      })
+      .catch((err: unknown) => {
+        if (cancelled) return;
+        setError(err instanceof Error ? err.message : String(err));
+        setLoading(false);
+      });
+    return () => {
+      cancelled = true;
+    };
+  }, [namespaceName]);
+
+  if (loading) {
+    return (
+      <SectionBox title="ArgoCD">
+        <StatusLabel status="warning">Loading...</StatusLabel>
+      </SectionBox>
+    );
+  }
+
+  if (error || !apps) {
+    return (
+      <SectionBox title="ArgoCD">
+        <StatusLabel status="error">ArgoCD unreachable</StatusLabel>
+      </SectionBox>
+    );
+  }
+
+  if (apps.length === 0) {
+    return null;
+  }
+
+  return (
+    <SectionBox title="ArgoCD">
+      <StatusLabel status="success">{apps.length} application(s)</StatusLabel>
+      <ul style={{ paddingLeft: 20, margin: "8px 0" }}>
+        {apps.map((app) => (
+          <li key={app.metadata.name} style={{ marginBottom: 8 }}>
+            <Link to={`/argocd/applications/${app.metadata.name}`}>
+              {app.metadata.name}
+            </Link>
+            &nbsp;
+            <StatusLabel
+              status={healthStatusToColor(
+                (app.status?.health?.status as
+                  | "Healthy"
+                  | "Degraded"
+                  | "Progressing"
+                  | "Missing"
+                  | "Unknown") ?? "Unknown"
+              )}
+            >
+              {healthStatusToLabel(
+                (app.status?.health?.status as
+                  | "Healthy"
+                  | "Degraded"
+                  | "Progressing"
+                  | "Missing"
+                  | "Unknown") ?? "Unknown"
+              )}
+            </StatusLabel>
+            &nbsp;
+            <StatusLabel
+              status={syncStatusToColor(
+                (app.status?.sync?.status as
+                  | "Synced"
+                  | "OutOfSync"
+                  | "Unknown") ?? "Unknown"
+              )}
+            >
+              {app.status?.sync?.status ?? "Unknown"}
+            </StatusLabel>
+          </li>
+        ))}
+      </ul>
+    </SectionBox>
+  );
+}
+
+// --- Deployment badge ---
+
+function DeploymentArgoBadge({ resource }: { resource: KubeObject }) {
+  const deploymentName = resource.metadata.name;
+  const [apps, setApps] = useState<ArgoCDApplication[] | null>(null);
+  const [loading, setLoading] = useState(true);
+  const [error, setError] = useState<string | null>(null);
+
+  useEffect(() => {
+    let cancelled = false;
+    fetchApplications()
+      .then((data) => {
+        if (cancelled) return;
+        const matched = (data.items ?? []).filter((app) =>
+          (app.status?.resources ?? []).some(
+            (res) => res.kind === "Deployment" && res.name === deploymentName
+          )
+        );
+        setApps(matched);
+        setLoading(false);
+      })
+      .catch((err: unknown) => {
+        if (cancelled) return;
+        setError(err instanceof Error ? err.message : String(err));
+        setLoading(false);
+      });
+    return () => {
+      cancelled = true;
+    };
+  }, [deploymentName]);
+
+  if (loading || error || !apps || apps.length === 0) {
+    return null;
+  }
+
+  const app = apps[0];
+  const lastSynced = app.status?.history?.length
+    ? app.status.history[app.status.history.length - 1]?.dexKey
+    : null;
+  const lastSyncedStr = lastSynced
+    ? new Date(lastSynced).toLocaleString()
+    : "—";
+
+  return (
+    <span>
+      &nbsp;
+      <Link to={`/argocd/applications/${app.metadata.name}`}>
+        ArgoCD: {app.metadata.name}
+      </Link>
+      &nbsp;
+      <StatusLabel
+        status={syncStatusToColor(
+          (app.status?.sync?.status as "Synced" | "OutOfSync" | "Unknown") ??
+            "Unknown"
+        )}
+      >
+        {app.status?.sync?.status ?? "Unknown"}
+      </StatusLabel>
+      &nbsp;
+      <span style={{ fontSize: "0.85em", opacity: 0.8 }}>
+        Last sync: {lastSyncedStr}
+      </span>
+    </span>
+  );
+}
+
+// --- Registration ---
+
+registerDetailsViewSection(({ resource }: { resource: KubeObject }) => {
+  if (resource.kind === "Namespace") {
+    return <NamespaceArgoSection resource={resource} />;
+  }
+
+  if (resource.kind === "Deployment") {
+    return <DeploymentArgoBadge resource={resource} />;
+  }
+
+  return null;
+});
diff --git a/src/index.tsx b/src/index.tsx
index 4526b1b..fdaf211 100644
--- a/src/index.tsx
+++ b/src/index.tsx
@@ -9,6 +9,7 @@ import {
 import React from "react";
 import ApplicationDetail from "./components/ApplicationDetail";
 import ApplicationsList from "./components/ApplicationsList";
+import "./components/PageInjections"; // side-effect: registers detail view sections
 
 // --- Error boundary for plugin components ---