diff --git a/libtaskmanager/taskfilterproxymodel.h b/libtaskmanager/taskfilterproxymodel.h
--- a/libtaskmanager/taskfilterproxymodel.h
+++ b/libtaskmanager/taskfilterproxymodel.h
@@ -53,6 +53,7 @@
     Q_PROPERTY(bool filterByScreen READ filterByScreen WRITE setFilterByScreen NOTIFY filterByScreenChanged)
     Q_PROPERTY(bool filterByActivity READ filterByActivity WRITE setFilterByActivity NOTIFY filterByActivityChanged)
     Q_PROPERTY(bool filterNotMinimized READ filterNotMinimized WRITE setFilterNotMinimized NOTIFY filterNotMinimizedChanged)
+    Q_PROPERTY(bool filterNotMaximized READ filterNotMaximized WRITE setFilterNotMaximized NOTIFY filterNotMaximizedChanged)
     Q_PROPERTY(bool filterSkipTaskbar READ filterSkipTaskbar WRITE setFilterSkipTaskbar NOTIFY filterSkipTaskbarChanged)
     Q_PROPERTY(bool filterSkipPager READ filterSkipPager WRITE setFilterSkipPager NOTIFY filterSkipPagerChanged)
 
@@ -212,6 +213,23 @@
      **/
     void setFilterNotMinimized(bool filter);
 
+    /**
+     * Whether non-maximized tasks should be filtered. Defaults to
+     * @c false.
+     *
+     * @see setFilterNotMaximized
+     * @returns @c true if non-maximized tasks should be filtered.
+     **/
+    bool filterNotMaximized() const;
+
+    /**
+     * Set whether non-maximized tasks should be filtered.
+     *
+     * @see filterNotMaximized
+     * @param filter Whether non-maximized tasks should be filtered.
+     **/
+    void setFilterNotMaximized(bool filter);
+
     /**
      * Whether tasks which should be omitted from 'task bars' should be
      * filtered. Defaults to @c true.
@@ -285,6 +303,7 @@
     void filterByScreenChanged() const;
     void filterByActivityChanged() const;
     void filterNotMinimizedChanged() const;
+    void filterNotMaximizedChanged() const;
     void filterSkipTaskbarChanged() const;
     void filterSkipPagerChanged() const;
     void demandingAttentionSkipsFiltersChanged() const;
diff --git a/libtaskmanager/taskfilterproxymodel.cpp b/libtaskmanager/taskfilterproxymodel.cpp
--- a/libtaskmanager/taskfilterproxymodel.cpp
+++ b/libtaskmanager/taskfilterproxymodel.cpp
@@ -41,6 +41,7 @@
     bool filterByScreen = false;
     bool filterByActivity = false;
     bool filterNotMinimized = false;
+    bool filterNotMaximized = false;
     bool filterSkipTaskbar = true;
     bool filterSkipPager = false;
 
@@ -186,6 +187,22 @@
     }
 }
 
+bool TaskFilterProxyModel::filterNotMaximized() const
+{
+    return d->filterNotMaximized;
+}
+
+void TaskFilterProxyModel::setFilterNotMaximized(bool filter)
+{
+    if (d->filterNotMaximized != filter) {
+        d->filterNotMaximized = filter;
+
+        invalidateFilter();
+
+        emit filterNotMaximizedChanged();
+    }
+}
+
 bool TaskFilterProxyModel::filterSkipTaskbar() const
 {
     return d->filterSkipTaskbar;
@@ -302,6 +319,15 @@
         }
     }
 
+    // Filter not maximized.
+    if (d->filterNotMaximized) {
+        bool isMaximized = sourceIdx.data(AbstractTasksModel::IsMaximized).toBool();
+
+        if (!isMaximized) {
+            return false;
+        }
+    }
+
     return true;
 }
 
diff --git a/libtaskmanager/tasksmodel.h b/libtaskmanager/tasksmodel.h
--- a/libtaskmanager/tasksmodel.h
+++ b/libtaskmanager/tasksmodel.h
@@ -74,6 +74,7 @@
     Q_PROPERTY(bool filterByScreen READ filterByScreen WRITE setFilterByScreen NOTIFY filterByScreenChanged)
     Q_PROPERTY(bool filterByActivity READ filterByActivity WRITE setFilterByActivity NOTIFY filterByActivityChanged)
     Q_PROPERTY(bool filterNotMinimized READ filterNotMinimized WRITE setFilterNotMinimized NOTIFY filterNotMinimizedChanged)
+    Q_PROPERTY(bool filterNotMaximized READ filterNotMaximized WRITE setFilterNotMaximized NOTIFY filterNotMaximized)
 
     Q_PROPERTY(SortMode sortMode READ sortMode WRITE setSortMode NOTIFY sortModeChanged)
     Q_PROPERTY(bool separateLaunchers READ separateLaunchers WRITE setSeparateLaunchers NOTIFY separateLaunchersChanged)
@@ -297,6 +298,23 @@
      **/
     void setFilterNotMinimized(bool filter);
 
+    /**
+     * Whether non-maximized tasks should be filtered. Defaults to
+     * @c false.
+     *
+     * @see setFilterNotMaximized
+     * @returns @c true if non-maximized tasks should be filtered.
+     **/
+    bool filterNotMaximized() const;
+
+    /**
+     * Set whether non-maximized tasks should be filtered.
+     *
+     * @see filterNotMaximized
+     * @param filter Whether non-maximized tasks should be filtered.
+     **/
+    void setFilterNotMaximized(bool filter);
+
     /**
      * The sort mode used in sorting tasks. Defaults to SortAlpha.
      *
@@ -852,6 +870,7 @@
     void filterByScreenChanged() const;
     void filterByActivityChanged() const;
     void filterNotMinimizedChanged() const;
+    void filterNotMaximizedChanged() const;
     void sortModeChanged() const;
     void separateLaunchersChanged() const;
     void launchInPlaceChanged() const;
diff --git a/libtaskmanager/tasksmodel.cpp b/libtaskmanager/tasksmodel.cpp
--- a/libtaskmanager/tasksmodel.cpp
+++ b/libtaskmanager/tasksmodel.cpp
@@ -316,6 +316,8 @@
         q, &TasksModel::filterByActivityChanged);
     QObject::connect(filterProxyModel, &TaskFilterProxyModel::filterNotMinimizedChanged,
         q, &TasksModel::filterNotMinimizedChanged);
+    QObject::connect(filterProxyModel, &TaskFilterProxyModel::filterNotMaximizedChanged,
+        q, &TasksModel::filterNotMaximizedChanged);
 
     groupingProxyModel = new TaskGroupingProxyModel(q);
     groupingProxyModel->setSourceModel(filterProxyModel);
@@ -1188,6 +1190,16 @@
     d->filterProxyModel->setFilterNotMinimized(filter);
 }
 
+bool TasksModel::filterNotMaximized() const
+{
+    return d->filterProxyModel->filterNotMaximized();
+}
+
+void TasksModel::setFilterNotMaximized(bool filter)
+{
+    d->filterProxyModel->setFilterNotMaximized(filter);
+}
+
 TasksModel::SortMode TasksModel::sortMode() const
 {
     return d->sortMode;