diff --git a/accessible/mac/mozAccessible.h b/accessible/mac/mozAccessible.h
index 6d7db3fe9863..d1424ba142da 100644
--- a/accessible/mac/mozAccessible.h
+++ b/accessible/mac/mozAccessible.h
@@ -114,6 +114,9 @@ static const uintptr_t IS_PROXY = 1;
 // the accessible description (help text) of this particular instance.
 - (NSString*)help;
 
+// returns the orientation (vertical, horizontal, or undefined)
+- (NSString*)orientation;
+
 - (BOOL)isEnabled;
 
 // information about focus.
diff --git a/accessible/mac/mozAccessible.mm b/accessible/mac/mozAccessible.mm
index 29d70764702b..8bd24463d3f5 100644
--- a/accessible/mac/mozAccessible.mm
+++ b/accessible/mac/mozAccessible.mm
@@ -323,6 +323,9 @@ ConvertToNSArray(nsTArray<ProxyAccessible*>& aArray)
   }
   if ([attribute isEqualToString:NSAccessibilityHelpAttribute])
     return [self help];
+  if ([attribute isEqualToString:NSAccessibilityOrientationAttribute])
+    return [self orientation];
+
   if ([attribute isEqualToString:NSAccessibilityDOMIdentifierAttribute]) {
     nsAutoString id;
     if (accWrap)
@@ -1067,6 +1070,28 @@ struct RoleDescrComparator
   NS_OBJC_END_TRY_ABORT_BLOCK_NIL;
 }
 
+- (NSString*)orientation
+{
+  NS_OBJC_BEGIN_TRY_ABORT_BLOCK_NIL;
+
+  uint64_t state;
+  if (AccessibleWrap* accWrap = [self getGeckoAccessible])
+    state = accWrap->InteractiveState();
+  else if (ProxyAccessible* proxy = [self getProxyAccessible])
+    state = proxy->State();
+  else
+    state = 0;
+
+  if (state & states::HORIZONTAL)
+    return NSAccessibilityHorizontalOrientationValue;
+  if (state & states::VERTICAL)
+    return NSAccessibilityVerticalOrientationValue;
+
+  return NSAccessibilityUnknownOrientationValue;
+
+  NS_OBJC_END_TRY_ABORT_BLOCK_NIL;
+}
+
 // objc-style description (from NSObject); not to be confused with the accessible description above.
 - (NSString*)description
 {