diff --git a/CMakeLists.txt b/CMakeLists.txt
index 653c1fd7578..d9de81ae463 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -157,6 +157,7 @@ add_compile_options(-Wlogical-op)
 add_compile_options(-Wmisleading-indentation)
 add_compile_options(-Wmissing-declarations)
 add_compile_options(-Wnon-virtual-dtor)
+add_compile_options(-Wsuggest-override)
 add_compile_options(-Wno-unknown-warning-option)
 add_compile_options(-Wundef)
 add_compile_options(-Wunused)
@@ -186,7 +187,6 @@ elseif (CMAKE_CXX_COMPILER_ID MATCHES "Clang$")
     add_compile_options(-Wno-atomic-alignment)
     add_compile_options(-Wno-c99-designator)
     add_compile_options(-Wno-implicit-const-int-float-conversion)
-    add_compile_options(-Wno-inconsistent-missing-override)
     add_compile_options(-Wno-null-pointer-subtraction)
     add_compile_options(-Wno-tautological-constant-out-of-range-compare)
     add_compile_options(-Wno-unneeded-internal-declaration)
diff --git a/Kernel/FileSystem/AnonymousFile.h b/Kernel/FileSystem/AnonymousFile.h
index a6e85810c83..a1346aef28a 100644
--- a/Kernel/FileSystem/AnonymousFile.h
+++ b/Kernel/FileSystem/AnonymousFile.h
@@ -24,7 +24,7 @@ public:
 
 private:
     virtual StringView class_name() const override { return "AnonymousFile"sv; }
-    virtual ErrorOr<NonnullOwnPtr<KString>> pseudo_path(const OpenFileDescription&) const;
+    virtual ErrorOr<NonnullOwnPtr<KString>> pseudo_path(const OpenFileDescription&) const override;
     virtual bool can_read(const OpenFileDescription&, size_t) const override { return false; }
     virtual bool can_write(const OpenFileDescription&, size_t) const override { return false; }
     virtual ErrorOr<size_t> read(OpenFileDescription&, u64, UserOrKernelBuffer&, size_t) override { return ENOTSUP; }
diff --git a/Kernel/FileSystem/ProcFS.h b/Kernel/FileSystem/ProcFS.h
index de4ca65c7a0..cc83c98cf0f 100644
--- a/Kernel/FileSystem/ProcFS.h
+++ b/Kernel/FileSystem/ProcFS.h
@@ -54,8 +54,8 @@ protected:
     ProcFS const& procfs() const { return static_cast<ProcFS const&>(Inode::fs()); }
 
     // ^Inode
-    virtual ErrorOr<void> attach(OpenFileDescription& description) = 0;
-    virtual void did_seek(OpenFileDescription&, off_t) = 0;
+    virtual ErrorOr<void> attach(OpenFileDescription& description) override = 0;
+    virtual void did_seek(OpenFileDescription&, off_t) override = 0;
     virtual ErrorOr<void> flush_metadata() override final;
     virtual ErrorOr<NonnullRefPtr<Inode>> create_child(StringView name, mode_t, dev_t, UserID, GroupID) override final;
     virtual ErrorOr<void> add_child(Inode&, StringView name, mode_t) override final;
diff --git a/Kernel/FileSystem/SysFS.h b/Kernel/FileSystem/SysFS.h
index eef4e4c88c0..00daf60e051 100644
--- a/Kernel/FileSystem/SysFS.h
+++ b/Kernel/FileSystem/SysFS.h
@@ -146,7 +146,7 @@ protected:
     virtual ErrorOr<void> chmod(mode_t) override;
     virtual ErrorOr<void> chown(UserID, GroupID) override;
     virtual ErrorOr<void> truncate(u64) override;
-    virtual ErrorOr<void> set_mtime(time_t);
+    virtual ErrorOr<void> set_mtime(time_t) override;
 
     virtual ErrorOr<void> attach(OpenFileDescription& description) override final;
     virtual void did_seek(OpenFileDescription&, off_t) override final;
diff --git a/Kernel/Firmware/PowerStateSwitch.h b/Kernel/Firmware/PowerStateSwitch.h
index e02db5138fd..7e167539fa1 100644
--- a/Kernel/Firmware/PowerStateSwitch.h
+++ b/Kernel/Firmware/PowerStateSwitch.h
@@ -26,7 +26,7 @@ public:
     virtual mode_t permissions() const override;
     virtual ErrorOr<size_t> write_bytes(off_t, size_t, UserOrKernelBuffer const&, OpenFileDescription*) override;
     virtual ErrorOr<void> truncate(u64) override;
-    virtual ErrorOr<void> set_mtime(time_t) { return {}; }
+    virtual ErrorOr<void> set_mtime(time_t) override { return {}; }
 
 private:
     PowerStateSwitchNode(FirmwareSysFSDirectory&);
diff --git a/Kernel/Graphics/GenericFramebufferDevice.h b/Kernel/Graphics/GenericFramebufferDevice.h
index c3a59c10fe5..7f9eb0c9d9e 100644
--- a/Kernel/Graphics/GenericFramebufferDevice.h
+++ b/Kernel/Graphics/GenericFramebufferDevice.h
@@ -29,7 +29,7 @@ public:
     virtual ~GenericFramebufferDevice() = default;
 
     // ^File
-    virtual ErrorOr<Memory::Region*> mmap(Process&, OpenFileDescription&, Memory::VirtualRange const&, u64 offset, int prot, bool shared) = 0;
+    virtual ErrorOr<Memory::Region*> mmap(Process&, OpenFileDescription&, Memory::VirtualRange const&, u64 offset, int prot, bool shared) override = 0;
     virtual ErrorOr<void> ioctl(OpenFileDescription&, unsigned request, Userspace<void*> arg) override final;
     virtual StringView class_name() const override final { return "FramebufferDevice"sv; }
 
diff --git a/Kernel/Graphics/VirtIOGPU/FramebufferDevice.h b/Kernel/Graphics/VirtIOGPU/FramebufferDevice.h
index dcec88e689a..e8aa88683d8 100644
--- a/Kernel/Graphics/VirtIOGPU/FramebufferDevice.h
+++ b/Kernel/Graphics/VirtIOGPU/FramebufferDevice.h
@@ -30,8 +30,8 @@ public:
 
     virtual ErrorOr<void> try_to_initialize() override { return {}; }
 
-    virtual void deactivate_writes();
-    virtual void activate_writes();
+    virtual void deactivate_writes() override;
+    virtual void activate_writes() override;
 
     size_t width() const { return display_info().rect.width; }
     size_t height() const { return display_info().rect.height; }
diff --git a/Kernel/Net/NE2000NetworkAdapter.h b/Kernel/Net/NE2000NetworkAdapter.h
index b29d3b514ac..f901a934ea1 100644
--- a/Kernel/Net/NE2000NetworkAdapter.h
+++ b/Kernel/Net/NE2000NetworkAdapter.h
@@ -31,12 +31,12 @@ public:
         // just assume that it's up.
         return true;
     }
-    virtual i32 link_speed()
+    virtual i32 link_speed() override
     {
         // Can only do 10mbit..
         return 10;
     }
-    virtual bool link_full_duplex() { return true; }
+    virtual bool link_full_duplex() override { return true; }
 
     virtual StringView purpose() const override { return class_name(); }
 
diff --git a/Meta/Lagom/Tools/CodeGenerators/IPCCompiler/main.cpp b/Meta/Lagom/Tools/CodeGenerators/IPCCompiler/main.cpp
index 0abc3bc693d..b3d47c1f8d4 100644
--- a/Meta/Lagom/Tools/CodeGenerators/IPCCompiler/main.cpp
+++ b/Meta/Lagom/Tools/CodeGenerators/IPCCompiler/main.cpp
@@ -416,7 +416,7 @@ public:
 )~~~");
 
             message_generator.append(R"~~~(
-    virtual bool valid() const { return m_ipc_message_valid; }
+    virtual bool valid() const override { return m_ipc_message_valid; }
 
     virtual IPC::MessageBuffer encode() const override
     {
diff --git a/Userland/Applications/SpaceAnalyzer/main.cpp b/Userland/Applications/SpaceAnalyzer/main.cpp
index ec41f9d4a53..d1b7297698d 100644
--- a/Userland/Applications/SpaceAnalyzer/main.cpp
+++ b/Userland/Applications/SpaceAnalyzer/main.cpp
@@ -35,17 +35,17 @@ struct TreeNode : public SpaceAnalyzer::TreeMapNode {
     TreeNode(String name)
         : m_name(move(name)) {};
 
-    virtual String name() const { return m_name; }
-    virtual i64 area() const { return m_area; }
-    virtual size_t num_children() const
+    virtual String name() const override { return m_name; }
+    virtual i64 area() const override { return m_area; }
+    virtual size_t num_children() const override
     {
         if (m_children) {
             return m_children->size();
         }
         return 0;
     }
-    virtual const TreeNode& child_at(size_t i) const { return m_children->at(i); }
-    virtual void sort_children_by_area() const
+    virtual const TreeNode& child_at(size_t i) const override { return m_children->at(i); }
+    virtual void sort_children_by_area() const override
     {
         if (m_children) {
             Vector<TreeNode>* children = const_cast<Vector<TreeNode>*>(m_children.ptr());
diff --git a/Userland/Applications/Terminal/main.cpp b/Userland/Applications/Terminal/main.cpp
index 12e9c154a10..786258d5ddb 100644
--- a/Userland/Applications/Terminal/main.cpp
+++ b/Userland/Applications/Terminal/main.cpp
@@ -51,7 +51,7 @@ public:
     {
     }
 
-    virtual void config_string_did_change(String const& domain, String const& group, String const& key, String const& value)
+    virtual void config_string_did_change(String const& domain, String const& group, String const& key, String const& value) override
     {
         VERIFY(domain == "Terminal");
 
@@ -77,7 +77,7 @@ public:
         }
     }
 
-    virtual void config_i32_did_change(String const& domain, String const& group, String const& key, i32 value)
+    virtual void config_i32_did_change(String const& domain, String const& group, String const& key, i32 value) override
     {
         VERIFY(domain == "Terminal");
 
diff --git a/Userland/DevTools/HackStudio/Git/GitFilesView.h b/Userland/DevTools/HackStudio/Git/GitFilesView.h
index 0901e4787e9..648cbfcb776 100644
--- a/Userland/DevTools/HackStudio/Git/GitFilesView.h
+++ b/Userland/DevTools/HackStudio/Git/GitFilesView.h
@@ -24,7 +24,7 @@ protected:
     GitFilesView(GitFileActionCallback, NonnullRefPtr<Gfx::Bitmap> action_icon);
 
 private:
-    virtual void paint_list_item(GUI::Painter& painter, int row_index, int painted_item_index);
+    virtual void paint_list_item(GUI::Painter& painter, int row_index, int painted_item_index) override;
 
     virtual void mousedown_event(GUI::MouseEvent&) override;
     virtual Gfx::IntRect action_icon_rect(size_t painted_item_index);
diff --git a/Userland/Libraries/LibChess/UCICommand.h b/Userland/Libraries/LibChess/UCICommand.h
index e591906e5cd..a72b78025ca 100644
--- a/Userland/Libraries/LibChess/UCICommand.h
+++ b/Userland/Libraries/LibChess/UCICommand.h
@@ -58,7 +58,7 @@ public:
 
     static UCICommand from_string(StringView command);
 
-    virtual String to_string() const;
+    virtual String to_string() const override;
 };
 
 class DebugCommand : public Command {
@@ -76,7 +76,7 @@ public:
 
     static DebugCommand from_string(StringView command);
 
-    virtual String to_string() const;
+    virtual String to_string() const override;
 
     Flag flag() const { return m_flag; }
 
@@ -93,7 +93,7 @@ public:
 
     static IsReadyCommand from_string(StringView command);
 
-    virtual String to_string() const;
+    virtual String to_string() const override;
 };
 
 class SetOptionCommand : public Command {
@@ -107,7 +107,7 @@ public:
 
     static SetOptionCommand from_string(StringView command);
 
-    virtual String to_string() const;
+    virtual String to_string() const override;
 
     const String& name() const { return m_name; }
     const Optional<String>& value() const { return m_value; }
@@ -128,7 +128,7 @@ public:
 
     static PositionCommand from_string(StringView command);
 
-    virtual String to_string() const;
+    virtual String to_string() const override;
 
     const Optional<String>& fen() const { return m_fen; }
     const Vector<Chess::Move>& moves() const { return m_moves; }
@@ -147,7 +147,7 @@ public:
 
     static GoCommand from_string(StringView command);
 
-    virtual String to_string() const;
+    virtual String to_string() const override;
 
     Optional<Vector<Chess::Move>> searchmoves;
     bool ponder { false };
@@ -172,7 +172,7 @@ public:
 
     static StopCommand from_string(StringView command);
 
-    virtual String to_string() const;
+    virtual String to_string() const override;
 };
 
 class IdCommand : public Command {
@@ -191,7 +191,7 @@ public:
 
     static IdCommand from_string(StringView command);
 
-    virtual String to_string() const;
+    virtual String to_string() const override;
 
     Type field_type() const { return m_field_type; }
     const String& value() const { return m_value; }
@@ -210,7 +210,7 @@ public:
 
     static UCIOkCommand from_string(StringView command);
 
-    virtual String to_string() const;
+    virtual String to_string() const override;
 };
 
 class ReadyOkCommand : public Command {
@@ -222,7 +222,7 @@ public:
 
     static ReadyOkCommand from_string(StringView command);
 
-    virtual String to_string() const;
+    virtual String to_string() const override;
 };
 
 class BestMoveCommand : public Command {
@@ -235,7 +235,7 @@ public:
 
     static BestMoveCommand from_string(StringView command);
 
-    virtual String to_string() const;
+    virtual String to_string() const override;
 
     Chess::Move move() const { return m_move; }
 
@@ -252,7 +252,7 @@ public:
 
     static InfoCommand from_string(StringView command);
 
-    virtual String to_string() const;
+    virtual String to_string() const override;
 
     Optional<int> depth;
     Optional<int> seldepth;
diff --git a/Userland/Libraries/LibCrypto/Checksum/Adler32.h b/Userland/Libraries/LibCrypto/Checksum/Adler32.h
index 97117766ab7..3c4595465be 100644
--- a/Userland/Libraries/LibCrypto/Checksum/Adler32.h
+++ b/Userland/Libraries/LibCrypto/Checksum/Adler32.h
@@ -27,8 +27,8 @@ public:
         update(data);
     }
 
-    void update(ReadonlyBytes data);
-    u32 digest();
+    virtual void update(ReadonlyBytes data) override;
+    virtual u32 digest() override;
 
 private:
     u32 m_state_a { 1 };
diff --git a/Userland/Libraries/LibCrypto/Checksum/CRC32.h b/Userland/Libraries/LibCrypto/Checksum/CRC32.h
index 885cf5bde5f..e2913527fde 100644
--- a/Userland/Libraries/LibCrypto/Checksum/CRC32.h
+++ b/Userland/Libraries/LibCrypto/Checksum/CRC32.h
@@ -55,8 +55,8 @@ public:
         update(data);
     }
 
-    void update(ReadonlyBytes data);
-    u32 digest();
+    virtual void update(ReadonlyBytes data) override;
+    virtual u32 digest() override;
 
 private:
     u32 m_state { ~0u };
diff --git a/Userland/Libraries/LibJS/Heap/Heap.cpp b/Userland/Libraries/LibJS/Heap/Heap.cpp
index 023f0aaf7ed..e616ecbb986 100644
--- a/Userland/Libraries/LibJS/Heap/Heap.cpp
+++ b/Userland/Libraries/LibJS/Heap/Heap.cpp
@@ -178,7 +178,7 @@ class MarkingVisitor final : public Cell::Visitor {
 public:
     MarkingVisitor() { }
 
-    virtual void visit_impl(Cell& cell)
+    virtual void visit_impl(Cell& cell) override
     {
         if (cell.is_marked())
             return;
diff --git a/Userland/Libraries/LibSQL/AST/AST.h b/Userland/Libraries/LibSQL/AST/AST.h
index b0ee4c72622..7dbcb7c3897 100644
--- a/Userland/Libraries/LibSQL/AST/AST.h
+++ b/Userland/Libraries/LibSQL/AST/AST.h
@@ -943,7 +943,7 @@ public:
     bool has_selection() const { return !m_select_statement.is_null(); }
     const RefPtr<Select>& select_statement() const { return m_select_statement; }
 
-    RefPtr<SQLResult> execute(ExecutionContext&) const;
+    virtual RefPtr<SQLResult> execute(ExecutionContext&) const override;
 
 private:
     RefPtr<CommonTableExpressionList> m_common_table_expression_list;
diff --git a/Userland/Libraries/LibWeb/CSS/CSSImportRule.h b/Userland/Libraries/LibWeb/CSS/CSSImportRule.h
index 3958c547089..1c6e37a55c4 100644
--- a/Userland/Libraries/LibWeb/CSS/CSSImportRule.h
+++ b/Userland/Libraries/LibWeb/CSS/CSSImportRule.h
@@ -35,8 +35,8 @@ public:
     const RefPtr<CSSStyleSheet> loaded_style_sheet() const { return m_style_sheet; }
     void set_style_sheet(const RefPtr<CSSStyleSheet>& style_sheet) { m_style_sheet = style_sheet; }
 
-    virtual StringView class_name() const { return "CSSImportRule"; };
-    virtual Type type() const { return Type::Import; };
+    virtual StringView class_name() const override { return "CSSImportRule"; };
+    virtual Type type() const override { return Type::Import; };
 
 private:
     explicit CSSImportRule(AK::URL, DOM::Document&);
diff --git a/Userland/Libraries/LibWeb/CSS/StyleValue.h b/Userland/Libraries/LibWeb/CSS/StyleValue.h
index 14f52b4a2fa..7ddc949809a 100644
--- a/Userland/Libraries/LibWeb/CSS/StyleValue.h
+++ b/Userland/Libraries/LibWeb/CSS/StyleValue.h
@@ -1345,7 +1345,7 @@ public:
         return m_values[i];
     }
 
-    virtual String to_string() const
+    virtual String to_string() const override
     {
         StringBuilder builder;
         builder.appendff("List[{}](", m_values.size());
diff --git a/Userland/Libraries/LibWeb/DOM/Document.h b/Userland/Libraries/LibWeb/DOM/Document.h
index 9f374ec385f..c1d93e3bdfa 100644
--- a/Userland/Libraries/LibWeb/DOM/Document.h
+++ b/Userland/Libraries/LibWeb/DOM/Document.h
@@ -171,7 +171,7 @@ public:
     const String& source() const { return m_source; }
     void set_source(const String& source) { m_source = source; }
 
-    JS::Realm& realm();
+    virtual JS::Realm& realm() override;
     JS::Interpreter& interpreter();
 
     JS::Value run_javascript(StringView source, StringView filename = "(unknown)");
diff --git a/Userland/Libraries/LibWeb/Layout/Box.h b/Userland/Libraries/LibWeb/Layout/Box.h
index d256ecbc734..71f2e65d85e 100644
--- a/Userland/Libraries/LibWeb/Layout/Box.h
+++ b/Userland/Libraries/LibWeb/Layout/Box.h
@@ -161,8 +161,8 @@ public:
 
     void clear_overflow_data() { m_overflow_data = nullptr; }
 
-    virtual void before_children_paint(PaintContext&, PaintPhase);
-    virtual void after_children_paint(PaintContext&, PaintPhase);
+    virtual void before_children_paint(PaintContext&, PaintPhase) override;
+    virtual void after_children_paint(PaintContext&, PaintPhase) override;
 
 protected:
     Box(DOM::Document& document, DOM::Node* node, NonnullRefPtr<CSS::StyleProperties> style)
diff --git a/Userland/Shell/Shell.cpp b/Userland/Shell/Shell.cpp
index 2d24d5c8114..ef4979a888d 100644
--- a/Userland/Shell/Shell.cpp
+++ b/Userland/Shell/Shell.cpp
@@ -1671,7 +1671,7 @@ void Shell::bring_cursor_to_beginning_of_a_line() const
 bool Shell::has_history_event(StringView source)
 {
     struct : public AST::NodeVisitor {
-        virtual void visit(const AST::HistoryEvent* node)
+        virtual void visit(const AST::HistoryEvent* node) override
         {
             has_history_event = true;
             AST::NodeVisitor::visit(node);