diff --git a/Userland/Libraries/LibWeb/CMakeLists.txt b/Userland/Libraries/LibWeb/CMakeLists.txt
index 5453182e4f..12e3941df5 100644
--- a/Userland/Libraries/LibWeb/CMakeLists.txt
+++ b/Userland/Libraries/LibWeb/CMakeLists.txt
@@ -12,6 +12,7 @@ set(SOURCES
     Bindings/ScriptExecutionContext.cpp
     Bindings/WindowObject.cpp
     Bindings/Wrappable.cpp
+    CSS/CSSGroupingRule.cpp
     CSS/CSSImportRule.cpp
     CSS/CSSRule.cpp
     CSS/CSSRuleList.cpp
diff --git a/Userland/Libraries/LibWeb/CSS/CSSGroupingRule.cpp b/Userland/Libraries/LibWeb/CSS/CSSGroupingRule.cpp
new file mode 100644
index 0000000000..59cc281c69
--- /dev/null
+++ b/Userland/Libraries/LibWeb/CSS/CSSGroupingRule.cpp
@@ -0,0 +1,33 @@
+/*
+ * Copyright (c) 2021, Sam Atkins <atkinssj@serenityos.org>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#include <LibWeb/CSS/CSSGroupingRule.h>
+#include <LibWeb/CSS/CSSRuleList.h>
+
+namespace Web::CSS {
+
+CSSGroupingRule::CSSGroupingRule(NonnullRefPtrVector<CSSRule>&& rules)
+    : m_rules(CSSRuleList { move(rules) })
+{
+}
+
+CSSGroupingRule::~CSSGroupingRule()
+{
+}
+
+size_t CSSGroupingRule::insert_rule(StringView const&, size_t)
+{
+    // https://www.w3.org/TR/cssom-1/#insert-a-css-rule
+    TODO();
+}
+
+void CSSGroupingRule::delete_rule(size_t)
+{
+    // https://www.w3.org/TR/cssom-1/#remove-a-css-rule
+    TODO();
+}
+
+}
diff --git a/Userland/Libraries/LibWeb/CSS/CSSGroupingRule.h b/Userland/Libraries/LibWeb/CSS/CSSGroupingRule.h
new file mode 100644
index 0000000000..e60a7ff8a3
--- /dev/null
+++ b/Userland/Libraries/LibWeb/CSS/CSSGroupingRule.h
@@ -0,0 +1,34 @@
+/*
+ * Copyright (c) 2021, Sam Atkins <atkinssj@serenityos.org>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#pragma once
+
+#include <AK/NonnullRefPtr.h>
+#include <LibWeb/CSS/CSSRule.h>
+#include <LibWeb/CSS/CSSRuleList.h>
+#include <LibWeb/Forward.h>
+
+namespace Web::CSS {
+
+class CSSGroupingRule : public CSSRule {
+    AK_MAKE_NONCOPYABLE(CSSGroupingRule);
+    AK_MAKE_NONMOVABLE(CSSGroupingRule);
+
+public:
+    ~CSSGroupingRule();
+
+    CSSRuleList const& css_rules() const { return m_rules; }
+    size_t insert_rule(StringView const& rule, size_t index = 0);
+    void delete_rule(size_t index);
+
+protected:
+    explicit CSSGroupingRule(NonnullRefPtrVector<CSSRule>&&);
+
+private:
+    CSSRuleList m_rules;
+};
+
+}
diff --git a/Userland/Libraries/LibWeb/CSS/CSSGroupingRule.idl b/Userland/Libraries/LibWeb/CSS/CSSGroupingRule.idl
new file mode 100644
index 0000000000..6c904e0f74
--- /dev/null
+++ b/Userland/Libraries/LibWeb/CSS/CSSGroupingRule.idl
@@ -0,0 +1,6 @@
+interface CSSGroupingRule : CSSRule {
+    [SameObject] readonly attribute CSSRuleList cssRules;
+    unsigned long insertRule(CSSOMString rule, optional unsigned long index = 0);
+    undefined deleteRule(unsigned long index);
+};
+