diff -r 736ab58641f0 -r 5c0b6af37b21 hgext3rd/topic/__init__.py
--- a/hgext3rd/topic/__init__.py	Mon Aug 28 17:10:41 2017 +0200
+++ b/hgext3rd/topic/__init__.py	Mon Aug 28 17:15:08 2017 +0200
@@ -312,6 +312,7 @@
         ('r', 'rev', '', 'revset of existing revisions', _('REV')),
         ('l', 'list', False, 'show the stack of changeset in the topic'),
         ('', 'age', False, 'show when you last touched the topics'),
+        ('', 'current', None, 'display the current topic only'),
     ] + commands.formatteropts,
     _('hg topics [TOPIC]'))
 def topics(ui, repo, topic='', clear=False, rev=None, list=False, **opts):
@@ -338,6 +339,13 @@
     The active topic (if any) will be prepended with a "*".
 
     The --verbose version of this command display various information on the state of each topic."""
+
+    current = opts.get('current')
+    if current and topic:
+        raise error.Abort(_("cannot use --current when setting a topic"))
+    if current and clear:
+        raise error.Abort(_("cannot use --current and --clear"))
+
     if list:
         if clear or rev:
             raise error.Abort(_("cannot use --clear or --rev with --list"))
@@ -375,7 +383,21 @@
     if topic:
         return _changecurrenttopic(repo, topic)
 
-    _listtopics(ui, repo, opts)
+    # `hg topic --current`
+    ret = 0
+    if current and not repo.currenttopic:
+        ui.write_err(_('no active topic\n'))
+        ret = 1
+    elif current:
+        fm = ui.formatter('topic', opts)
+        namemask = '%s\n'
+        label = 'topic.active'
+        fm.startitem()
+        fm.write('topic', namemask, repo.currenttopic, label=label)
+        fm.end()
+    else:
+        _listtopics(ui, repo, opts)
+    return ret
 
 @command('stack', [
     ] + commands.formatteropts,