The Supernatural actor - who appeared in two-part story 'The Impossible Astronaut / Day of the Moon' - told Digital Spy that ex-FBI agent Canton Everett Delaware III had been "a wonderful character to play".
Asked if he would consider a potential return, Sheppard said: "Of course, absolutely - who wouldn't? I was asked to participate in something I've loved since I was a kid and it was a joy to do."
However, Sheppard admitted that he is uncertain if Who showrunner Steven Moffat is planning on bringing Canton back.
"I was just talking to Steven - nobody's ever sure what Mr Moffat wants to do, and he's always done exactly what he wants to do," said the 48-year-old.
"I'm a fan of both of his current shows [Doctor Who and Sherlock] and enjoy not only being a part of his world, but... watching it regardless."
Doctor Who is expected to return to BBC One in August. The series airs on BBC America in the US.