diff --git a/components/script/dom/document.rs b/components/script/dom/document.rs
index 1fda0761c66..be57cf45ae4 100644
--- a/components/script/dom/document.rs
+++ b/components/script/dom/document.rs
@@ -105,7 +105,7 @@ use string_cache::{Atom, QualName};
 use style::restyle_hints::ElementSnapshot;
 use style::stylesheets::Stylesheet;
 use time;
-use url::Url;
+use url::{Host, Url};
 use util::str::{DOMString, split_html_space_chars, str_join};
 
 #[derive(JSTraceable, PartialEq, HeapSizeOf)]
@@ -1647,6 +1647,19 @@ impl DocumentMethods for Document {
         }
     }
 
+    // https://html.spec.whatwg.org/multipage/#relaxing-the-same-origin-restriction
+    fn Domain(&self) -> DOMString {
+        // TODO: This should use the effective script origin when it exists
+        let origin = self.window.get_url();
+
+        if let Some(&Host::Ipv6(ipv6)) = origin.host() {
+            // Omit square brackets for IPv6 addresses.
+            return DOMString::from(ipv6.serialize());
+        }
+
+        DOMString::from(origin.serialize_host().unwrap_or_else(|| "".to_owned()))
+    }
+
     // https://dom.spec.whatwg.org/#dom-document-documenturi
     fn DocumentURI(&self) -> DOMString {
         self.URL()
diff --git a/components/script/dom/webidls/Document.webidl b/components/script/dom/webidls/Document.webidl
index 5ccd72d087d..328c54b1c2e 100644
--- a/components/script/dom/webidls/Document.webidl
+++ b/components/script/dom/webidls/Document.webidl
@@ -81,7 +81,7 @@ partial /*sealed*/ interface Document {
   // resource metadata management
   // [PutForwards=href, Unforgeable]
   readonly attribute Location/*?*/ location;
-  // attribute DOMString domain;
+  readonly attribute DOMString domain;
   // readonly attribute DOMString referrer;
   [Throws]
   attribute DOMString cookie;
diff --git a/tests/wpt/metadata/MANIFEST.json b/tests/wpt/metadata/MANIFEST.json
index 40ae2ccd47e..f9e15ea99fb 100644
--- a/tests/wpt/metadata/MANIFEST.json
+++ b/tests/wpt/metadata/MANIFEST.json
@@ -29953,6 +29953,12 @@
     "deleted": [],
     "items": {
       "testharness": {
+        "html/browsers/origin/relaxing-the-same-origin-restriction/document_domain.html": [
+          {
+            "path": "html/browsers/origin/relaxing-the-same-origin-restriction/document_domain.html",
+            "url": "/html/browsers/origin/relaxing-the-same-origin-restriction/document_domain.html"
+          }
+        ],
         "html/semantics/forms/form-submission-0/url-encoded.html": [
           {
             "path": "html/semantics/forms/form-submission-0/url-encoded.html",
diff --git a/tests/wpt/metadata/XMLHttpRequest/send-after-setting-document-domain.htm.ini b/tests/wpt/metadata/XMLHttpRequest/send-after-setting-document-domain.htm.ini
deleted file mode 100644
index 4114af649a9..00000000000
--- a/tests/wpt/metadata/XMLHttpRequest/send-after-setting-document-domain.htm.ini
+++ /dev/null
@@ -1,5 +0,0 @@
-[send-after-setting-document-domain.htm]
-  type: testharness
-  [loading documents from original origin after setting document.domain]
-    expected: FAIL
-
diff --git a/tests/wpt/metadata/html/browsers/origin/relaxing-the-same-origin-restriction/document_domain.html.ini b/tests/wpt/metadata/html/browsers/origin/relaxing-the-same-origin-restriction/document_domain.html.ini
new file mode 100644
index 00000000000..81f58d2ecba
--- /dev/null
+++ b/tests/wpt/metadata/html/browsers/origin/relaxing-the-same-origin-restriction/document_domain.html.ini
@@ -0,0 +1,4 @@
+[document_domain.html]
+  type: testharness
+  [new document]
+    expected: FAIL
diff --git a/tests/wpt/metadata/html/dom/interfaces.html.ini b/tests/wpt/metadata/html/dom/interfaces.html.ini
index eedba2f8c04..8f863d110c5 100644
--- a/tests/wpt/metadata/html/dom/interfaces.html.ini
+++ b/tests/wpt/metadata/html/dom/interfaces.html.ini
@@ -9003,9 +9003,6 @@
   [Document interface: document.implementation.createDocument(null, "", null) must inherit property "enableStyleSheetsForSet" with the proper type (33)]
     expected: FAIL
 
-  [Document interface: document.implementation.createDocument(null, "", null) must inherit property "domain" with the proper type (35)]
-    expected: FAIL
-
   [Document interface: document.implementation.createDocument(null, "", null) must inherit property "referrer" with the proper type (36)]
     expected: FAIL
 
diff --git a/tests/wpt/web-platform-tests/html/browsers/origin/relaxing-the-same-origin-restriction/document_domain.html b/tests/wpt/web-platform-tests/html/browsers/origin/relaxing-the-same-origin-restriction/document_domain.html
new file mode 100644
index 00000000000..af933217336
--- /dev/null
+++ b/tests/wpt/web-platform-tests/html/browsers/origin/relaxing-the-same-origin-restriction/document_domain.html
@@ -0,0 +1,25 @@
+<!doctype html>
+<html>
+    <head>
+        <title></title>
+        <script src="/resources/testharness.js"></script>
+        <script src="/resources/testharnessreport.js"></script>
+        <script>
+            test(function() {
+                assert_equals(typeof document.domain, "string", "document.domain is a string");
+                assert_not_equals(document.domain, "", "document.domain is not empty");
+            }, "sanity checks");
+
+            test(function() {
+                assert_equals(document.domain, window.location.hostname, "equals location.hostname");
+            }, "current document");
+
+            test(function() {
+                var doc = new Document();
+                assert_equals(doc.domain, "", "new document has empty domain");
+            }, "new document");
+        </script>
+    </head>
+    <body>
+    </body>
+</html>