The Daleks' Master Plan is the mostly missing fourth serial of the third season in the British science fiction television series Doctor Who, which originally aired in twelve weekly parts from 13 November 1965 to 29 January 1966. This twelve-part serial is the longest with a single director and production code (The Trial of a Time Lord was longer but was made in three production blocks, with separate codes, and with four separate story lines each with their own authors and working titles).

Several portions of the long-running British science-fiction television programme Doctor Who are no longer held by the BBC. Between 1967 and 1978, the BBC routinely deleted archive programmes for various practical reasons—lack of space, scarcity of materials, and a lack of rebroadcast rights. As a result, 97 of 253 episodes from the programme's first six years are currently missing, primarily from Seasons 3, 4 and 5, leaving 26 serials incomplete. Many more were considered lost until recovered from various sources, mostly overseas broadcasters.