diff --git a/autotests/client/test_plasma_window_model.cpp b/autotests/client/test_plasma_window_model.cpp
--- a/autotests/client/test_plasma_window_model.cpp
+++ b/autotests/client/test_plasma_window_model.cpp
@@ -79,6 +79,7 @@
     void testGeometry();
     void testTitle();
     void testAppId();
+    void testPid();
     void testVirtualDesktop();
     // TODO icon: can we ensure a theme is installed on CI?
     void testRequests();
@@ -220,6 +221,7 @@
     QTest::newRow("decoration") << int(Qt::DecorationRole) << QByteArrayLiteral("DecorationRole");
 
     QTest::newRow("AppId")                << int(PlasmaWindowModel::AppId) << QByteArrayLiteral("AppId");
+    QTest::newRow("Pid")                  << int(PlasmaWindowModel::Pid) << QByteArrayLiteral("Pid");
     QTest::newRow("IsActive")             << int(PlasmaWindowModel::IsActive) << QByteArrayLiteral("IsActive");
     QTest::newRow("IsFullscreenable")     << int(PlasmaWindowModel::IsFullscreenable) << QByteArrayLiteral("IsFullscreenable");
     QTest::newRow("IsFullscreen")         << int(PlasmaWindowModel::IsFullscreen) << QByteArrayLiteral("IsFullscreen");
@@ -332,6 +334,7 @@
     QTest::newRow("IsVirtualDesktopChangeable") << int(PlasmaWindowModel::IsVirtualDesktopChangeable) << QVariant(false);
     QTest::newRow("IsCloseable")          << int(PlasmaWindowModel::IsCloseable) << QVariant(false);
     QTest::newRow("Geometry")             << int(PlasmaWindowModel::Geometry) << QVariant(QRect());
+    QTest::newRow("Pid")                  << int(PlasmaWindowModel::Pid) << QVariant(0);
 }
 
 void PlasmaWindowModelTest::testDefaultData()
@@ -521,6 +524,31 @@
     QCOMPARE(model->data(index, PlasmaWindowModel::AppId).toString(), QStringLiteral("org.kde.testapp"));
 }
 
+void PlasmaWindowModelTest::testPid()
+{
+    auto model = m_pw->createWindowModel();
+    QVERIFY(model);
+    QSignalSpy rowInsertedSpy(model, &PlasmaWindowModel::rowsInserted);
+    QVERIFY(rowInsertedSpy.isValid());
+    auto w = m_pwInterface->createWindow(m_pwInterface);
+    QVERIFY(w);
+    QVERIFY(rowInsertedSpy.wait());
+    m_connection->flush();
+    m_display->dispatchEvents();
+    QSignalSpy dataChangedSpy(model, &PlasmaWindowModel::dataChanged);
+    QVERIFY(dataChangedSpy.isValid());
+
+    const QModelIndex index = model->index(0);
+    QCOMPARE(model->data(index, PlasmaWindowModel::Pid).toInt(), 0);
+
+    w->setPid(1337);
+    QVERIFY(dataChangedSpy.wait());
+    QCOMPARE(dataChangedSpy.count(), 1);
+    QCOMPARE(dataChangedSpy.last().first().toModelIndex(), index);
+    QCOMPARE(dataChangedSpy.last().last().value<QVector<int>>(), QVector<int>{int(PlasmaWindowModel::Pid)});
+    QCOMPARE(model->data(index, PlasmaWindowModel::Pid).toInt(), 1337);
+}
+
 void PlasmaWindowModelTest::testVirtualDesktop()
 {
     auto model = m_pw->createWindowModel();
diff --git a/autotests/client/test_wayland_windowmanagement.cpp b/autotests/client/test_wayland_windowmanagement.cpp
--- a/autotests/client/test_wayland_windowmanagement.cpp
+++ b/autotests/client/test_wayland_windowmanagement.cpp
@@ -67,6 +67,7 @@
     void testParentWindow();
     void testGeometry();
     void testIcon();
+    void testPid();
 
     void cleanup();
 
@@ -581,5 +582,24 @@
     QCOMPARE(m_window->icon().name(), QStringLiteral("xorg"));
 }
 
+void TestWindowManagement::testPid()
+{
+    using namespace KWayland::Client;
+    QVERIFY(m_window);
+    QVERIFY(m_windowInterface);
+    QVERIFY(m_window->pid() == 0);
+    QSignalSpy pidChangedSpy(m_window, &PlasmaWindow::pidChanged);
+    QVERIFY(pidChangedSpy.isValid());
+    // doing nothing does nothing
+    QVERIFY(!pidChangedSpy.wait(10));
+    m_windowInterface->setPid(1984);
+    QVERIFY(pidChangedSpy.wait());
+    QVERIFY(m_window->pid() == 1984);
+    // no signal when the same value is set twice
+    m_windowInterface->setPid(1984);
+    QVERIFY(!pidChangedSpy.wait(10));
+    QVERIFY(m_window->pid() == 1984);
+}
+
 QTEST_MAIN(TestWindowManagement)
 #include "test_wayland_windowmanagement.moc"
diff --git a/src/client/plasmawindowmanagement.h b/src/client/plasmawindowmanagement.h
--- a/src/client/plasmawindowmanagement.h
+++ b/src/client/plasmawindowmanagement.h
@@ -380,6 +380,12 @@
      * @since 5.22
      */
     bool isVirtualDesktopChangeable() const;
+    /**
+     * @returns The process id this window belongs to.
+     * @see pidChanged
+     * @since 5.35
+     */
+    quint32 pid() const;
 
     /**
      * Requests to activate the window.
@@ -470,6 +476,12 @@
      **/
     void appIdChanged();
     /**
+     * The process id changed.
+     * @see pid
+     * @since 5.35
+     **/
+    void pidChanged();
+    /**
      * The virtual desktop changed.
      * @see virtualDesktop
      **/
diff --git a/src/client/plasmawindowmanagement.cpp b/src/client/plasmawindowmanagement.cpp
--- a/src/client/plasmawindowmanagement.cpp
+++ b/src/client/plasmawindowmanagement.cpp
@@ -93,10 +93,12 @@
     QPointer<PlasmaWindow> parentWindow;
     QMetaObject::Connection parentWindowUnmappedConnection;
     QRect geometry;
+    quint32 pid = 0;
 
 private:
     static void titleChangedCallback(void *data, org_kde_plasma_window *window, const char *title);
     static void appIdChangedCallback(void *data, org_kde_plasma_window *window, const char *app_id);
+    static void pidChangedCallback(void *data, org_kde_plasma_window *window, uint32_t pid);
     static void stateChangedCallback(void *data, org_kde_plasma_window *window, uint32_t state);
     static void virtualDesktopChangedCallback(void *data, org_kde_plasma_window *window, int32_t number);
     static void themedIconNameChangedCallback(void *data, org_kde_plasma_window *window, const char *name);
@@ -124,6 +126,7 @@
     void setResizable(bool set);
     void setVirtualDesktopChangeable(bool set);
     void setParentWindow(PlasmaWindow *parentWindow);
+    void setPid(const quint32 pid);
 
     static Private *cast(void *data) {
         return reinterpret_cast<Private*>(data);
@@ -341,7 +344,8 @@
     initialStateCallback,
     parentWindowCallback,
     windowGeometryCallback,
-    iconChangedCallback
+    iconChangedCallback,
+    pidChangedCallback
 };
 
 void PlasmaWindow::Private::parentWindowCallback(void *data, org_kde_plasma_window *window, org_kde_plasma_window *parent)
@@ -422,6 +426,17 @@
     emit p->q->appIdChanged();
 }
 
+void PlasmaWindow::Private::pidChangedCallback(void *data, org_kde_plasma_window *window, uint32_t pid)
+{
+    Q_UNUSED(window)
+    Private *p = cast(data);
+    if (p->pid == static_cast<quint32>(pid)) {
+        return;
+    }
+    p->pid = pid;
+    emit p->q->pidChanged();
+}
+
 void PlasmaWindow::Private::virtualDesktopChangedCallback(void *data, org_kde_plasma_window *window, int32_t number)
 {
     Q_UNUSED(window)
@@ -749,6 +764,11 @@
     return d->appId;
 }
 
+quint32 PlasmaWindow::pid() const
+{
+    return d->pid;
+}
+
 QString PlasmaWindow::title() const
 {
     return d->title;
diff --git a/src/client/plasmawindowmodel.h b/src/client/plasmawindowmodel.h
--- a/src/client/plasmawindowmodel.h
+++ b/src/client/plasmawindowmodel.h
@@ -101,7 +101,11 @@
         /**
         * @since 5.25
         */
-        Geometry
+        Geometry,
+        /**
+         * @since 5.35
+         */
+        Pid
     };
     Q_ENUM(AdditionalRoles)
 
diff --git a/src/client/plasmawindowmodel.cpp b/src/client/plasmawindowmodel.cpp
--- a/src/client/plasmawindowmodel.cpp
+++ b/src/client/plasmawindowmodel.cpp
@@ -225,6 +225,8 @@
         return window->icon();
     } else if (role == AppId) {
         return window->appId();
+    } else if (role == Pid) {
+        return window->pid();
     } else if (role == IsActive) {
         return window->isActive();
     } else if (role == IsFullscreenable) {
diff --git a/src/client/protocols/plasma-window-management.xml b/src/client/protocols/plasma-window-management.xml
--- a/src/client/protocols/plasma-window-management.xml
+++ b/src/client/protocols/plasma-window-management.xml
@@ -17,7 +17,7 @@
     along with this program.  If not, see <http://www.gnu.org/licenses/>.
   ]]></copyright>
 
-  <interface name="org_kde_plasma_window_management" version="7">
+  <interface name="org_kde_plasma_window_management" version="8">
     <description summary="application windows management">
       This interface manages application windows.
       It provides requests to show and hide the desktop and emits
@@ -257,5 +257,15 @@
             The client can request the icon using get_icon.
         </description>
     </event>
+
+    <event name="pid_changed">
+      <description summary="process id of application owning the window has changed">
+        This event will be sent when the compositor has set the process id this window belongs to.
+        The pid will initially be 0, meaning it has not been set. As the compositor sets it, the client
+        gets notified.
+      </description>
+      <arg name="pid" type="uint" summary="process id"/>
+    </event>
+
   </interface>
 </protocol>
diff --git a/src/server/plasmawindowmanagement_interface.h b/src/server/plasmawindowmanagement_interface.h
--- a/src/server/plasmawindowmanagement_interface.h
+++ b/src/server/plasmawindowmanagement_interface.h
@@ -87,6 +87,7 @@
 
     void setTitle(const QString &title);
     void setAppId(const QString &appId);
+    void setPid(quint32 pid);
     void setVirtualDesktop(quint32 desktop);
     void setActive(bool set);
     void setMinimized(bool set);
diff --git a/src/server/plasmawindowmanagement_interface.cpp b/src/server/plasmawindowmanagement_interface.cpp
--- a/src/server/plasmawindowmanagement_interface.cpp
+++ b/src/server/plasmawindowmanagement_interface.cpp
@@ -72,6 +72,7 @@
     void createResource(wl_resource *parent, uint32_t id);
     void setTitle(const QString &title);
     void setAppId(const QString &appId);
+    void setPid(quint32 pid);
     void setThemedIconName(const QString &iconName);
     void setIcon(const QIcon &icon);
     void setVirtualDesktop(quint32 desktop);
@@ -109,6 +110,7 @@
     PlasmaWindowInterface *q;
     QString m_title;
     QString m_appId;
+    quint32 m_pid = 0;
     QString m_themedIconName;
     QIcon m_icon;
     quint32 m_virtualDesktop = 0;
@@ -329,6 +331,9 @@
     if (!m_appId.isEmpty()) {
         org_kde_plasma_window_send_app_id_changed(resource, m_appId.toUtf8().constData());
     }
+    if (m_pid != 0) {
+        org_kde_plasma_window_send_pid_changed(resource, m_pid);
+    }
     if (!m_title.isEmpty()) {
         org_kde_plasma_window_send_title_changed(resource, m_title.toUtf8().constData());
     }
@@ -369,6 +374,17 @@
     }
 }
 
+void PlasmaWindowInterface::Private::setPid(quint32 pid)
+{
+    if (m_pid == pid) {
+        return;
+    }
+    m_pid = pid;
+    for (auto it = resources.constBegin(); it != resources.constEnd(); ++it) {
+        org_kde_plasma_window_send_pid_changed(*it, pid);
+    }
+}
+
 void PlasmaWindowInterface::Private::setThemedIconName(const QString &iconName)
 {
     if (m_themedIconName == iconName) {
@@ -655,6 +671,11 @@
     d->setAppId(appId);
 }
 
+void PlasmaWindowInterface::setPid(quint32 pid)
+{
+    d->setPid(pid);
+}
+
 void PlasmaWindowInterface::setTitle(const QString &title)
 {
     d->setTitle(title);