diff --git a/Libraries/LibWeb/CSS/Interpolation.cpp b/Libraries/LibWeb/CSS/Interpolation.cpp
index e68d82c2101..7d148e29141 100644
--- a/Libraries/LibWeb/CSS/Interpolation.cpp
+++ b/Libraries/LibWeb/CSS/Interpolation.cpp
@@ -15,6 +15,7 @@
 #include <LibWeb/CSS/StyleValues/CSSColorValue.h>
 #include <LibWeb/CSS/StyleValues/CSSKeywordValue.h>
 #include <LibWeb/CSS/StyleValues/CalculatedStyleValue.h>
+#include <LibWeb/CSS/StyleValues/FontStyleStyleValue.h>
 #include <LibWeb/CSS/StyleValues/FrequencyStyleValue.h>
 #include <LibWeb/CSS/StyleValues/IntegerStyleValue.h>
 #include <LibWeb/CSS/StyleValues/LengthStyleValue.h>
@@ -161,6 +162,13 @@ ValueComparingRefPtr<CSSStyleValue const> interpolate_property(DOM::Element& ele
         if (property_id == PropertyID::BoxShadow)
             return interpolate_box_shadow(element, calculation_context, from, to, delta);
 
+        if (property_id == PropertyID::FontStyle) {
+            auto static oblique_0deg_value = FontStyleStyleValue::create(FontStyle::Oblique, AngleStyleValue::create(Angle::make_degrees(0)));
+            auto from_value = from->as_font_style().font_style() == FontStyle::Normal ? oblique_0deg_value : from;
+            auto to_value = to->as_font_style().font_style() == FontStyle::Normal ? oblique_0deg_value : to;
+            return interpolate_value(element, calculation_context, from_value, to_value, delta);
+        }
+
         if (property_id == PropertyID::Scale)
             return interpolate_scale(element, calculation_context, from, to, delta);
 
@@ -689,6 +697,17 @@ static RefPtr<CSSStyleValue const> interpolate_value_impl(DOM::Element& element,
 
         return delta >= 0.5f ? to : from;
     }
+    case CSSStyleValue::Type::FontStyle: {
+        auto const& from_font_style = from.as_font_style();
+        auto const& to_font_style = to.as_font_style();
+        auto interpolated_font_style = interpolate_value(element, calculation_context, CSSKeywordValue::create(to_keyword(from_font_style.font_style())), CSSKeywordValue::create(to_keyword(to_font_style.font_style())), delta);
+        if (from_font_style.angle() && to_font_style.angle()) {
+            auto interpolated_angle = interpolate_value(element, calculation_context, *from_font_style.angle(), *to_font_style.angle(), delta);
+            return FontStyleStyleValue::create(*keyword_to_font_style(interpolated_font_style->to_keyword()), interpolated_angle);
+        }
+
+        return FontStyleStyleValue::create(*keyword_to_font_style(interpolated_font_style->to_keyword()));
+    }
     case CSSStyleValue::Type::Integer: {
         // https://drafts.csswg.org/css-values/#combine-integers
         // Interpolation of <integer> is defined as Vresult = round((1 - p) × VA + p × VB);
diff --git a/Tests/LibWeb/Text/expected/wpt-import/css/css-fonts/animations/font-style-interpolation.txt b/Tests/LibWeb/Text/expected/wpt-import/css/css-fonts/animations/font-style-interpolation.txt
new file mode 100644
index 00000000000..3383b93d56c
--- /dev/null
+++ b/Tests/LibWeb/Text/expected/wpt-import/css/css-fonts/animations/font-style-interpolation.txt
@@ -0,0 +1,135 @@
+Harness status: OK
+
+Found 129 tests
+
+116 Pass
+13 Fail
+Pass	CSS Transitions: property <font-style> from [normal] to [oblique 10deg] at (-2) should be [oblique -20deg]
+Pass	CSS Transitions: property <font-style> from [normal] to [oblique 10deg] at (-0.25) should be [oblique -2.5deg]
+Pass	CSS Transitions: property <font-style> from [normal] to [oblique 10deg] at (0) should be [normal]
+Pass	CSS Transitions: property <font-style> from [normal] to [oblique 10deg] at (0.3) should be [oblique 3deg]
+Pass	CSS Transitions: property <font-style> from [normal] to [oblique 10deg] at (0.6) should be [oblique 6deg]
+Pass	CSS Transitions: property <font-style> from [normal] to [oblique 10deg] at (1) should be [oblique 10deg]
+Pass	CSS Transitions: property <font-style> from [normal] to [oblique 10deg] at (1.5) should be [oblique 15deg]
+Pass	CSS Transitions with transition: all: property <font-style> from [normal] to [oblique 10deg] at (-2) should be [oblique -20deg]
+Pass	CSS Transitions with transition: all: property <font-style> from [normal] to [oblique 10deg] at (-0.25) should be [oblique -2.5deg]
+Pass	CSS Transitions with transition: all: property <font-style> from [normal] to [oblique 10deg] at (0) should be [normal]
+Pass	CSS Transitions with transition: all: property <font-style> from [normal] to [oblique 10deg] at (0.3) should be [oblique 3deg]
+Pass	CSS Transitions with transition: all: property <font-style> from [normal] to [oblique 10deg] at (0.6) should be [oblique 6deg]
+Pass	CSS Transitions with transition: all: property <font-style> from [normal] to [oblique 10deg] at (1) should be [oblique 10deg]
+Pass	CSS Transitions with transition: all: property <font-style> from [normal] to [oblique 10deg] at (1.5) should be [oblique 15deg]
+Pass	CSS Animations: property <font-style> from [normal] to [oblique 10deg] at (-2) should be [oblique -20deg]
+Pass	CSS Animations: property <font-style> from [normal] to [oblique 10deg] at (-0.25) should be [oblique -2.5deg]
+Pass	CSS Animations: property <font-style> from [normal] to [oblique 10deg] at (0) should be [normal]
+Pass	CSS Animations: property <font-style> from [normal] to [oblique 10deg] at (0.3) should be [oblique 3deg]
+Pass	CSS Animations: property <font-style> from [normal] to [oblique 10deg] at (0.6) should be [oblique 6deg]
+Pass	CSS Animations: property <font-style> from [normal] to [oblique 10deg] at (1) should be [oblique 10deg]
+Pass	CSS Animations: property <font-style> from [normal] to [oblique 10deg] at (1.5) should be [oblique 15deg]
+Pass	Web Animations: property <font-style> from [normal] to [oblique 10deg] at (-2) should be [oblique -20deg]
+Pass	Web Animations: property <font-style> from [normal] to [oblique 10deg] at (-0.25) should be [oblique -2.5deg]
+Pass	Web Animations: property <font-style> from [normal] to [oblique 10deg] at (0) should be [normal]
+Pass	Web Animations: property <font-style> from [normal] to [oblique 10deg] at (0.3) should be [oblique 3deg]
+Pass	Web Animations: property <font-style> from [normal] to [oblique 10deg] at (0.6) should be [oblique 6deg]
+Pass	Web Animations: property <font-style> from [normal] to [oblique 10deg] at (1) should be [oblique 10deg]
+Pass	Web Animations: property <font-style> from [normal] to [oblique 10deg] at (1.5) should be [oblique 15deg]
+Pass	CSS Transitions: property <font-style> from [oblique 5deg] to [oblique 15deg] at (-2) should be [oblique -15deg]
+Pass	CSS Transitions: property <font-style> from [oblique 5deg] to [oblique 15deg] at (-0.25) should be [oblique 2.5deg]
+Pass	CSS Transitions: property <font-style> from [oblique 5deg] to [oblique 15deg] at (0) should be [oblique 5deg]
+Pass	CSS Transitions: property <font-style> from [oblique 5deg] to [oblique 15deg] at (0.3) should be [oblique 8deg]
+Pass	CSS Transitions: property <font-style> from [oblique 5deg] to [oblique 15deg] at (0.6) should be [oblique 11deg]
+Pass	CSS Transitions: property <font-style> from [oblique 5deg] to [oblique 15deg] at (1) should be [oblique 15deg]
+Pass	CSS Transitions: property <font-style> from [oblique 5deg] to [oblique 15deg] at (1.5) should be [oblique 20deg]
+Pass	CSS Transitions with transition: all: property <font-style> from [oblique 5deg] to [oblique 15deg] at (-2) should be [oblique -15deg]
+Pass	CSS Transitions with transition: all: property <font-style> from [oblique 5deg] to [oblique 15deg] at (-0.25) should be [oblique 2.5deg]
+Pass	CSS Transitions with transition: all: property <font-style> from [oblique 5deg] to [oblique 15deg] at (0) should be [oblique 5deg]
+Pass	CSS Transitions with transition: all: property <font-style> from [oblique 5deg] to [oblique 15deg] at (0.3) should be [oblique 8deg]
+Pass	CSS Transitions with transition: all: property <font-style> from [oblique 5deg] to [oblique 15deg] at (0.6) should be [oblique 11deg]
+Pass	CSS Transitions with transition: all: property <font-style> from [oblique 5deg] to [oblique 15deg] at (1) should be [oblique 15deg]
+Pass	CSS Transitions with transition: all: property <font-style> from [oblique 5deg] to [oblique 15deg] at (1.5) should be [oblique 20deg]
+Pass	CSS Animations: property <font-style> from [oblique 5deg] to [oblique 15deg] at (-2) should be [oblique -15deg]
+Pass	CSS Animations: property <font-style> from [oblique 5deg] to [oblique 15deg] at (-0.25) should be [oblique 2.5deg]
+Pass	CSS Animations: property <font-style> from [oblique 5deg] to [oblique 15deg] at (0) should be [oblique 5deg]
+Pass	CSS Animations: property <font-style> from [oblique 5deg] to [oblique 15deg] at (0.3) should be [oblique 8deg]
+Pass	CSS Animations: property <font-style> from [oblique 5deg] to [oblique 15deg] at (0.6) should be [oblique 11deg]
+Pass	CSS Animations: property <font-style> from [oblique 5deg] to [oblique 15deg] at (1) should be [oblique 15deg]
+Pass	CSS Animations: property <font-style> from [oblique 5deg] to [oblique 15deg] at (1.5) should be [oblique 20deg]
+Pass	Web Animations: property <font-style> from [oblique 5deg] to [oblique 15deg] at (-2) should be [oblique -15deg]
+Pass	Web Animations: property <font-style> from [oblique 5deg] to [oblique 15deg] at (-0.25) should be [oblique 2.5deg]
+Pass	Web Animations: property <font-style> from [oblique 5deg] to [oblique 15deg] at (0) should be [oblique 5deg]
+Pass	Web Animations: property <font-style> from [oblique 5deg] to [oblique 15deg] at (0.3) should be [oblique 8deg]
+Pass	Web Animations: property <font-style> from [oblique 5deg] to [oblique 15deg] at (0.6) should be [oblique 11deg]
+Pass	Web Animations: property <font-style> from [oblique 5deg] to [oblique 15deg] at (1) should be [oblique 15deg]
+Pass	Web Animations: property <font-style> from [oblique 5deg] to [oblique 15deg] at (1.5) should be [oblique 20deg]
+Pass	CSS Transitions: property <font-style> from [initial] to [inherit] at (-2) should be [oblique -40deg]
+Pass	CSS Transitions: property <font-style> from [initial] to [inherit] at (-0.25) should be [oblique -5deg]
+Pass	CSS Transitions: property <font-style> from [initial] to [inherit] at (0) should be [normal]
+Pass	CSS Transitions: property <font-style> from [initial] to [inherit] at (0.3) should be [oblique 6deg]
+Pass	CSS Transitions: property <font-style> from [initial] to [inherit] at (0.6) should be [oblique 12deg]
+Pass	CSS Transitions: property <font-style> from [initial] to [inherit] at (1) should be [oblique 20deg]
+Pass	CSS Transitions: property <font-style> from [initial] to [inherit] at (1.5) should be [oblique 30deg]
+Pass	CSS Transitions with transition: all: property <font-style> from [initial] to [inherit] at (-2) should be [oblique -40deg]
+Pass	CSS Transitions with transition: all: property <font-style> from [initial] to [inherit] at (-0.25) should be [oblique -5deg]
+Pass	CSS Transitions with transition: all: property <font-style> from [initial] to [inherit] at (0) should be [normal]
+Pass	CSS Transitions with transition: all: property <font-style> from [initial] to [inherit] at (0.3) should be [oblique 6deg]
+Pass	CSS Transitions with transition: all: property <font-style> from [initial] to [inherit] at (0.6) should be [oblique 12deg]
+Pass	CSS Transitions with transition: all: property <font-style> from [initial] to [inherit] at (1) should be [oblique 20deg]
+Pass	CSS Transitions with transition: all: property <font-style> from [initial] to [inherit] at (1.5) should be [oblique 30deg]
+Pass	CSS Animations: property <font-style> from [initial] to [inherit] at (-2) should be [oblique -40deg]
+Pass	CSS Animations: property <font-style> from [initial] to [inherit] at (-0.25) should be [oblique -5deg]
+Pass	CSS Animations: property <font-style> from [initial] to [inherit] at (0) should be [normal]
+Pass	CSS Animations: property <font-style> from [initial] to [inherit] at (0.3) should be [oblique 6deg]
+Pass	CSS Animations: property <font-style> from [initial] to [inherit] at (0.6) should be [oblique 12deg]
+Pass	CSS Animations: property <font-style> from [initial] to [inherit] at (1) should be [oblique 20deg]
+Pass	CSS Animations: property <font-style> from [initial] to [inherit] at (1.5) should be [oblique 30deg]
+Pass	Web Animations: property <font-style> from [initial] to [inherit] at (-2) should be [oblique -40deg]
+Pass	Web Animations: property <font-style> from [initial] to [inherit] at (-0.25) should be [oblique -5deg]
+Pass	Web Animations: property <font-style> from [initial] to [inherit] at (0) should be [normal]
+Pass	Web Animations: property <font-style> from [initial] to [inherit] at (0.3) should be [oblique 6deg]
+Pass	Web Animations: property <font-style> from [initial] to [inherit] at (0.6) should be [oblique 12deg]
+Pass	Web Animations: property <font-style> from [initial] to [inherit] at (1) should be [oblique 20deg]
+Pass	Web Animations: property <font-style> from [initial] to [inherit] at (1.5) should be [oblique 30deg]
+Pass	CSS Transitions: property <font-style> from [oblique 20deg] to [normal] at (-1) should be [oblique 40deg]
+Pass	CSS Transitions: property <font-style> from [oblique 20deg] to [normal] at (0) should be [oblique 20deg]
+Pass	CSS Transitions: property <font-style> from [oblique 20deg] to [normal] at (0.5) should be [oblique 10deg]
+Pass	CSS Transitions: property <font-style> from [oblique 20deg] to [normal] at (1) should be [normal]
+Pass	CSS Transitions: property <font-style> from [oblique 20deg] to [normal] at (1.5) should be [oblique -10deg]
+Pass	CSS Transitions with transition: all: property <font-style> from [oblique 20deg] to [normal] at (-1) should be [oblique 40deg]
+Pass	CSS Transitions with transition: all: property <font-style> from [oblique 20deg] to [normal] at (0) should be [oblique 20deg]
+Pass	CSS Transitions with transition: all: property <font-style> from [oblique 20deg] to [normal] at (0.5) should be [oblique 10deg]
+Pass	CSS Transitions with transition: all: property <font-style> from [oblique 20deg] to [normal] at (1) should be [normal]
+Pass	CSS Transitions with transition: all: property <font-style> from [oblique 20deg] to [normal] at (1.5) should be [oblique -10deg]
+Pass	CSS Animations: property <font-style> from [oblique 20deg] to [normal] at (-1) should be [oblique 40deg]
+Pass	CSS Animations: property <font-style> from [oblique 20deg] to [normal] at (0) should be [oblique 20deg]
+Pass	CSS Animations: property <font-style> from [oblique 20deg] to [normal] at (0.5) should be [oblique 10deg]
+Pass	CSS Animations: property <font-style> from [oblique 20deg] to [normal] at (1) should be [normal]
+Pass	CSS Animations: property <font-style> from [oblique 20deg] to [normal] at (1.5) should be [oblique -10deg]
+Pass	Web Animations: property <font-style> from [oblique 20deg] to [normal] at (-1) should be [oblique 40deg]
+Pass	Web Animations: property <font-style> from [oblique 20deg] to [normal] at (0) should be [oblique 20deg]
+Pass	Web Animations: property <font-style> from [oblique 20deg] to [normal] at (0.5) should be [oblique 10deg]
+Pass	Web Animations: property <font-style> from [oblique 20deg] to [normal] at (1) should be [normal]
+Pass	Web Animations: property <font-style> from [oblique 20deg] to [normal] at (1.5) should be [oblique -10deg]
+Fail	CSS Transitions: property <font-style> from [oblique -90deg] to [oblique 90deg] at (-2) should be [oblique -90deg]
+Fail	CSS Transitions: property <font-style> from [oblique -90deg] to [oblique 90deg] at (-1) should be [oblique -90deg]
+Pass	CSS Transitions: property <font-style> from [oblique -90deg] to [oblique 90deg] at (0) should be [oblique -90deg]
+Pass	CSS Transitions: property <font-style> from [oblique -90deg] to [oblique 90deg] at (0.5) should be [normal]
+Pass	CSS Transitions: property <font-style> from [oblique -90deg] to [oblique 90deg] at (1) should be [oblique 90deg]
+Fail	CSS Transitions: property <font-style> from [oblique -90deg] to [oblique 90deg] at (1.5) should be [oblique 90deg]
+Fail	CSS Transitions with transition: all: property <font-style> from [oblique -90deg] to [oblique 90deg] at (-2) should be [oblique -90deg]
+Fail	CSS Transitions with transition: all: property <font-style> from [oblique -90deg] to [oblique 90deg] at (-1) should be [oblique -90deg]
+Pass	CSS Transitions with transition: all: property <font-style> from [oblique -90deg] to [oblique 90deg] at (0) should be [oblique -90deg]
+Pass	CSS Transitions with transition: all: property <font-style> from [oblique -90deg] to [oblique 90deg] at (0.5) should be [normal]
+Pass	CSS Transitions with transition: all: property <font-style> from [oblique -90deg] to [oblique 90deg] at (1) should be [oblique 90deg]
+Fail	CSS Transitions with transition: all: property <font-style> from [oblique -90deg] to [oblique 90deg] at (1.5) should be [oblique 90deg]
+Fail	CSS Animations: property <font-style> from [oblique -90deg] to [oblique 90deg] at (-2) should be [oblique -90deg]
+Fail	CSS Animations: property <font-style> from [oblique -90deg] to [oblique 90deg] at (-1) should be [oblique -90deg]
+Pass	CSS Animations: property <font-style> from [oblique -90deg] to [oblique 90deg] at (0) should be [oblique -90deg]
+Pass	CSS Animations: property <font-style> from [oblique -90deg] to [oblique 90deg] at (0.5) should be [normal]
+Pass	CSS Animations: property <font-style> from [oblique -90deg] to [oblique 90deg] at (1) should be [oblique 90deg]
+Fail	CSS Animations: property <font-style> from [oblique -90deg] to [oblique 90deg] at (1.5) should be [oblique 90deg]
+Fail	Web Animations: property <font-style> from [oblique -90deg] to [oblique 90deg] at (-2) should be [oblique -90deg]
+Fail	Web Animations: property <font-style> from [oblique -90deg] to [oblique 90deg] at (-1) should be [oblique -90deg]
+Pass	Web Animations: property <font-style> from [oblique -90deg] to [oblique 90deg] at (0) should be [oblique -90deg]
+Pass	Web Animations: property <font-style> from [oblique -90deg] to [oblique 90deg] at (0.5) should be [normal]
+Pass	Web Animations: property <font-style> from [oblique -90deg] to [oblique 90deg] at (1) should be [oblique 90deg]
+Fail	Web Animations: property <font-style> from [oblique -90deg] to [oblique 90deg] at (1.5) should be [oblique 90deg]
+Fail	An interpolation to inherit updates correctly on a parent style change.
\ No newline at end of file
diff --git a/Tests/LibWeb/Text/input/wpt-import/css/css-fonts/animations/font-style-interpolation.html b/Tests/LibWeb/Text/input/wpt-import/css/css-fonts/animations/font-style-interpolation.html
new file mode 100644
index 00000000000..3af5ef499ec
--- /dev/null
+++ b/Tests/LibWeb/Text/input/wpt-import/css/css-fonts/animations/font-style-interpolation.html
@@ -0,0 +1,122 @@
+<!DOCTYPE html>
+<meta charset="UTF-8">
+<title>font-style interpolation</title>
+<link rel="help" href="https://drafts.csswg.org/css-fonts-3/#propdef-font-style">
+<meta name="assert" content="Font-style should be animated smoothly.">
+
+<script src="../../../resources/testharness.js"></script>
+<script src="../../../resources/testharnessreport.js"></script>
+<script src="../../../css/support/interpolation-testcommon.js"></script>
+
+<style>
+.container {
+  font-style: oblique 20deg;
+}
+.container2 {
+  font-style: oblique 5deg;
+}
+.target {
+  display: inline-block;
+  font: 100px sans-serif;
+  font-style: normal;
+}
+.expected {
+  color: green;
+  margin-right: 30px;
+}
+</style>
+
+<body>
+<template id="target-template">
+  <span class="container">
+    <div class="target">TT</div>
+  </span>
+</template>
+
+<span id="inv-container" class="container">
+  <div id="inv-target" class="target">TT</div>
+</span>
+</body>
+
+<script>
+test_interpolation({
+  property: 'font-style',
+  from: 'normal',
+  to: 'oblique 10deg'
+}, [
+  {at: -2, expect: 'oblique -20deg'},
+  {at: -0.25, expect: 'oblique -2.5deg'},
+  {at: 0, expect: 'normal'},
+  {at: 0.3, expect: 'oblique 3deg'},
+  {at: 0.6, expect: 'oblique 6deg'},
+  {at: 1, expect: 'oblique 10deg'},
+  {at: 1.5, expect: 'oblique 15deg'},
+]);
+
+test_interpolation({
+  property: 'font-style',
+  from: 'oblique 5deg',
+  to: 'oblique 15deg'
+}, [
+  { at: -2, expect: 'oblique -15deg' },
+  { at: -0.25, expect: 'oblique 2.5deg' },
+  { at: 0, expect: 'oblique 5deg' },
+  { at: 0.3, expect: 'oblique 8deg' },
+  { at: 0.6, expect: 'oblique 11deg' },
+  { at: 1, expect: 'oblique 15deg' },
+  { at: 1.5, expect: 'oblique 20deg' },
+]);
+
+test_interpolation({
+  property: 'font-style',
+  from: 'initial',
+  to: 'inherit'
+}, [
+  { at: -2, expect: 'oblique -40deg' },
+  { at: -0.25, expect: 'oblique -5deg' },
+  { at: 0, expect: 'normal' },
+  { at: 0.3, expect: 'oblique 6deg' },
+  { at: 0.6, expect: 'oblique 12deg' },
+  { at: 1, expect: 'oblique 20deg' },
+  { at: 1.5, expect: 'oblique 30deg' },
+]);
+
+test_interpolation({
+  property: 'font-style',
+  from: 'oblique 20deg',
+  to: 'normal'
+}, [
+  { at: -1, expect: 'oblique 40deg' },
+  { at: 0, expect: 'oblique 20deg' },
+  { at: 0.5, expect: 'oblique 10deg' },
+  { at: 1, expect: 'normal' },
+  { at: 1.5, expect: 'oblique -10deg' },
+]);
+
+test_interpolation({
+  property: 'font-style',
+  from: 'oblique -90deg',
+  to: 'oblique 90deg'
+}, [
+  { at: -2, expect: 'oblique -90deg' },
+  { at: -1, expect: 'oblique -90deg' },
+  { at: 0, expect: 'oblique -90deg' },
+  { at: 0.5, expect: 'normal' },
+  { at: 1, expect: 'oblique 90deg' },
+  { at: 1.5, expect: 'oblique 90deg' },
+]);
+
+test(t => {
+  var container = document.getElementById('inv-container');
+  var target = document.getElementById('inv-target');
+  var anim = target.animate({ fontStyle: ['normal', 'inherit'] }, 1000);
+  anim.pause();
+  anim.currentTime = 500;
+  assert_equals(getComputedStyle(target).fontStyle, 'oblique 10deg');
+
+  container.setAttribute('class', 'container2');
+  assert_equals(getComputedStyle(target).fontStyle, 'oblique 2.5deg');
+}, "An interpolation to inherit updates correctly on a parent style change.");
+
+</script>
+