The outage appears to have begun around 9 p.m. ET, according to outage monitors and comments on Twitter.
Users of the app are also unable to use the service.
As yet we have no word from YouTube on what the problem is related to or if there's an estimated time on a fix.
No further information has been provided on what is causing tonight's outage, how long it will last.
YouTube, an American video-sharing website headquartered in San Bruno, California, was founded by three former PayPal employees - Chad Hurley, Steve Chen, and Jawed Karim - in February 2005.
Say goodbye to all your favourite let's players, game walkthroughs and new game trailers, YouTube is down! The site's official launch was in November 2005 and in less than a year, about 65,000 videos were being uploaded on a daily basis.