No, he does not. He is single according to his myspace page: the official Zachary quinto myspace page which can be found by going to his website, www.zacharyquinto.com and linking to his myspace page...
From everything I've read he's been single since 2006... any romances he's had recently he's done a great job of hiding from the media...
He had a fling with Rumer Willis for about a day in March...