Unknown. The Doctor is known to have married River Song ("The Wedding of River Song") and Queen Elizabeth I prior to "The End of Time", but in "Blink" the Doctor makes an additional reference to being married. Oh, and he also accidentally married Marilyn Monroe in "A Christmas Carol", but he doesn't think it was official. The Doctor has a granddaughter, Susan (with the recent "The Rings of Akhaten" reaffirming this after some spin-off media suggesting this wasn't their true relation), but one does not need to be married in order to have a grandchild. It is possible that one or more of the original novels made reference to a wife as well. He proposes to an Aztec lady in "The Aztecs" accidentally, but he did like her.