Tennant, who played the 10th Doctor in the long-running British TV Series "Doctor Who," actually married a previous Doctor's daughter. Georgia Moffett is the daughter of Peter Davison, who played the Doctor in the years between 1982 and 1984.
Georgia appeared on the show, playing the Doctor's cloned daughter. Funnily enough, even though the actress is the daughter of the 1984 Doctor Who actor, she played the daughter of the then Doctor Who actor, David Tennant. Apparently the episode went over so well that they hit it off. They were reportedly engaged on January 2011, then they had a daughter together in March of 2011 and finally got married on December of that year.