diff --git a/Base/home/anon/www/first-child.html b/Base/home/anon/www/first-child.html
new file mode 100644
index 0000000000..553d814668
--- /dev/null
+++ b/Base/home/anon/www/first-child.html
@@ -0,0 +1,24 @@
+<html>
+<head>
+<title>:first-child test</title>
+<style>
+p:first-child {
+  color: lime;
+  background-color: black;
+  padding: 5px;
+}
+</style>
+</head>
+<body>
+<div>
+  <p>This text is selected!</p>
+  <p>This text isn't selected.</p>
+</div>
+
+<div>
+  <h2>This text isn't selected: it's not a `p`.</h2>
+  <p>This text isn't selected.</p>
+</div>
+
+</body>
+</html>
diff --git a/Base/home/anon/www/last-child.html b/Base/home/anon/www/last-child.html
new file mode 100644
index 0000000000..562d85aac4
--- /dev/null
+++ b/Base/home/anon/www/last-child.html
@@ -0,0 +1,23 @@
+<html>
+<head>
+<title>:last-child test</title>
+<style>
+p:last-child {
+  color: lime;
+  background-color: black;
+  padding: 5px;
+}
+</style>
+</head>
+<body>
+<div>
+  <p>This text isn't selected.</p>
+  <p>This text is selected!</p>
+</div>
+
+<div>
+  <p>This text isn't selected.</p>
+  <h2>This text isn't selected: it's not a `p`.</h2>
+</div>
+</body>
+</html>
diff --git a/Base/home/anon/www/welcome.html b/Base/home/anon/www/welcome.html
index d11541fc1c..1fbecdd0ca 100644
--- a/Base/home/anon/www/welcome.html
+++ b/Base/home/anon/www/welcome.html
@@ -24,6 +24,8 @@ h1 {
     <p>Some small test pages:</p>
     <ul>
         <li><a href="small.html">small</a></li>
+        <li><a href="first-child.html">:first-child</a></li>
+        <li><a href="last-child.html">:last-child</a></li>
         <li><a href="form.html">form</a></li>
         <li><a href="borders.html">borders</a></li>
         <li><a href="css.html">css</a></li>
diff --git a/Libraries/LibHTML/CSS/Selector.h b/Libraries/LibHTML/CSS/Selector.h
index 288f16a9a5..e0e68e2be6 100644
--- a/Libraries/LibHTML/CSS/Selector.h
+++ b/Libraries/LibHTML/CSS/Selector.h
@@ -20,6 +20,8 @@ public:
             None,
             Link,
             Hover,
+            FirstChild,
+            LastChild,
         };
         PseudoClass pseudo_class { PseudoClass::None };
 
diff --git a/Libraries/LibHTML/CSS/SelectorEngine.cpp b/Libraries/LibHTML/CSS/SelectorEngine.cpp
index f33018607d..affedd2128 100644
--- a/Libraries/LibHTML/CSS/SelectorEngine.cpp
+++ b/Libraries/LibHTML/CSS/SelectorEngine.cpp
@@ -27,6 +27,14 @@ bool matches(const Selector::SimpleSelector& component, const Element& element)
         if (!matches_hover_pseudo_class(element))
             return false;
         break;
+    case Selector::SimpleSelector::PseudoClass::FirstChild:
+        if (element.previous_element_sibling())
+            return false;
+        break;
+    case Selector::SimpleSelector::PseudoClass::LastChild:
+        if (element.next_element_sibling())
+            return false;
+        break;
     }
 
     switch (component.attribute_match_type) {
diff --git a/Libraries/LibHTML/Parser/CSSParser.cpp b/Libraries/LibHTML/Parser/CSSParser.cpp
index 786c713591..6cfc93c75a 100644
--- a/Libraries/LibHTML/Parser/CSSParser.cpp
+++ b/Libraries/LibHTML/Parser/CSSParser.cpp
@@ -321,6 +321,10 @@ public:
                 simple_selector.pseudo_class = Selector::SimpleSelector::PseudoClass::Link;
             else if (pseudo_name == "hover")
                 simple_selector.pseudo_class = Selector::SimpleSelector::PseudoClass::Hover;
+            else if (pseudo_name == "first-child")
+                simple_selector.pseudo_class = Selector::SimpleSelector::PseudoClass::FirstChild;
+            else if (pseudo_name == "last-child")
+                simple_selector.pseudo_class = Selector::SimpleSelector::PseudoClass::LastChild;
         }
 
         return simple_selector;
