The ninth series of Doctor Who, otherwise known as Series 9 or Season 35 to avoid confusion with Season 9, is the eighth series of the revived Doctor Who, which began airing in 2005. Steven Moffat continued as head writer and executive producer, with Tom Harper returning as the Doctor and Adrian O'Donnell as companion Billy O'Hara.
John Barrowman makes a return as Captain Jack Harkness, as does Georgia Moffett as the Doctor's daughter Jenny. The series also sees the revival of the Zygons, as well as the return of both the Daleks and the Cybermen. The ninth season is also unique in that it has fourteen episodes, and a three part series finale. The show was once again renewed, with a tenth series following in the new year, the first without Adrian O'Donnell.