"The Lodger" is the eleventh episode of the fifth series of the British science fiction television series Doctor Who, first broadcast on BBC One on 12 June 2010. It was written by Gareth Roberts, who based the story on his 2006 Doctor Who Magazine comic strip "The Lodger".

The fifth series of the British science-fiction television programme Doctor Who was originally broadcast on BBC One in 2010. The series began on 3 April 2010 with "The Eleventh Hour", and ended with "The Big Bang" on 26 June 2010. The series is the first to be led by Steven Moffat, who took over as head writer and executive producer when Russell T Davies ended his involvement in the show after "The End of Time". The series has 13 episodes, six of which were written by Moffat. Piers Wenger and Beth Willis were co-executive producers, and Tracie Simpson and Peter Bennett were producers. Although it is the fifth series since the show's revival in 2005, the series' production code numbers were reset.