"The Sontaran Stratagem" is the fourth episode of the fourth series of the British science fiction television series Doctor Who, which depicts the adventures of a time-travelling humanoid alien known as The Doctor. The episode was broadcast on BBC One on 26 April 2008. The episode and its sequel, "The Poison Sky", were written by Helen Raynor, who previously wrote the linked episodes "Daleks in Manhattan" and "Evolution of the Daleks" in the third series.

The fourth series of British science fiction television programme Doctor Who was preceded by the 2007 Christmas special "Voyage of the Damned". Following the special, a regular series of thirteen episodes aired, starting with "Partners in Crime" on 5 April 2008 and ending with "Journey's End" three months later on 5 July 2008. The series incorporates a loose story arc consisting of recurring mentions of the disappearance of various planets and moons.