diff --git a/dom/security/featurepolicy/FeaturePolicy.cpp b/dom/security/featurepolicy/FeaturePolicy.cpp
index 30aa2beb51fb..1bd546e3b61c 100644
--- a/dom/security/featurepolicy/FeaturePolicy.cpp
+++ b/dom/security/featurepolicy/FeaturePolicy.cpp
@@ -148,6 +148,16 @@ bool FeaturePolicy::AllowsFeatureInternal(const nsAString& aFeatureName,
   return false;
 }
 
+void FeaturePolicy::Features(nsTArray<nsString>& aFeatures) {
+  RefPtr<FeaturePolicy> self = this;
+  FeaturePolicyUtils::ForEachFeature(
+      [self, &aFeatures](const char* aFeatureName) {
+        nsString featureName;
+        featureName.AppendASCII(aFeatureName);
+        aFeatures.AppendElement(featureName);
+      });
+}
+
 void FeaturePolicy::AllowedFeatures(nsTArray<nsString>& aAllowedFeatures) {
   RefPtr<FeaturePolicy> self = this;
   FeaturePolicyUtils::ForEachFeature(
diff --git a/dom/security/featurepolicy/FeaturePolicy.h b/dom/security/featurepolicy/FeaturePolicy.h
index 3856cd25d173..1fe517e3a3af 100644
--- a/dom/security/featurepolicy/FeaturePolicy.h
+++ b/dom/security/featurepolicy/FeaturePolicy.h
@@ -113,6 +113,8 @@ class FeaturePolicy final : public nsISupports, public nsWrapperCache {
   bool AllowsFeature(const nsAString& aFeatureName,
                      const Optional<nsAString>& aOrigin) const;
 
+  void Features(nsTArray<nsString>& aFeatures);
+
   void AllowedFeatures(nsTArray<nsString>& aAllowedFeatures);
 
   void GetAllowlistForFeature(const nsAString& aFeatureName,
diff --git a/dom/security/featurepolicy/test/mochitest/mochitest.ini b/dom/security/featurepolicy/test/mochitest/mochitest.ini
index 3402c8662f4b..a9598fd7ee39 100644
--- a/dom/security/featurepolicy/test/mochitest/mochitest.ini
+++ b/dom/security/featurepolicy/test/mochitest/mochitest.ini
@@ -8,3 +8,4 @@ support-files =
   test_parser.html^headers^
 
 [test_parser.html]
+[test_featureList.html]
diff --git a/dom/security/featurepolicy/test/mochitest/test_featureList.html b/dom/security/featurepolicy/test/mochitest/test_featureList.html
new file mode 100644
index 000000000000..ed51d67092d9
--- /dev/null
+++ b/dom/security/featurepolicy/test/mochitest/test_featureList.html
@@ -0,0 +1,42 @@
+<!DOCTYPE HTML>
+<html>
+<head>
+  <title>Test feature policy - list</title>
+  <script type="text/javascript" src="/tests/SimpleTest/SimpleTest.js"></script>
+  <link rel="stylesheet" type="text/css" href="/tests/SimpleTest/test.css" />
+</head>
+<body>
+<iframe src="empty.html" id="ifr"></iframe>
+<script type="text/javascript">
+
+let supportedFeatures = [
+  "autoplay",
+  "camera",
+  "encrypted-media",
+  "fullscreen",
+  "geolocation",
+  "microphone",
+  "midi",
+  "payment",
+  "display-capture",
+  "document-domain",
+  "speaker",
+  "vr",
+];
+
+function checkFeatures(features) {
+  features.forEach(feature => {
+    ok(supportedFeatures.includes(feature), "Feature: " + feature);
+  });
+}
+
+ok("featurePolicy" in document, "We have document.featurePolicy");
+checkFeatures(document.featurePolicy.features());
+
+let ifr = document.getElementById("ifr");
+ok("featurePolicy" in ifr, "We have HTMLIFrameElement.featurePolicy");
+checkFeatures(ifr.featurePolicy.features());
+
+</script>
+</body>
+</html>
diff --git a/dom/webidl/FeaturePolicy.webidl b/dom/webidl/FeaturePolicy.webidl
index 85a3b82ce892..e89f56b6ded8 100644
--- a/dom/webidl/FeaturePolicy.webidl
+++ b/dom/webidl/FeaturePolicy.webidl
@@ -10,6 +10,7 @@
 [NoInterfaceObject]
 interface FeaturePolicy {
   boolean allowsFeature(DOMString feature, optional DOMString origin);
+  sequence<DOMString> features();
   sequence<DOMString> allowedFeatures();
   sequence<DOMString> getAllowlistForFeature(DOMString feature);
 };
