The Time Meddler is the ninth and final serial of the second season of the British science fiction television series Doctor Who. Written by Dennis Spooner and directed by Douglas Camfield, the serial was broadcast on BBC1 in four weekly parts from 3 to 24 July 1965. Set in Northumbria in 1066, before the Battle of Stamford Bridge, the serial features the time traveller the First Doctor and his companions Vicki and Steven Taylor as they attempt to outwit the time traveller the Monk, who is plotting to change the course of European history by wiping out King Harald Hardrada's Viking invasion fleet, leaving Harold Godwinson and the Saxon soldiers fresh to defeat William of Normandy and the Norman soldiers at the Battle of Hastings.

The second season of British science fiction television series Doctor Who was originally broadcast on BBC1 between 1964 and 1965. The season began on 31 October 1964 with Planet of Giants and ended with The Time Meddler on 24 July 1965. Like the first season, production was overseen by the BBC's first female producer Verity Lambert. Story editor David Whitaker continued to handle the scripts and stories during early production, handing over to Dennis Spooner as the season began to air; Spooner subsequently left his role by the season's end, and was replaced by Donald Tosh for its final serial. By the season's end, Lambert was the only remaining production member from the team responsible for creating the series.