Highlander: The Source (released in some countries as Highlander 5: The Source) is a 2007 American science fantasy action adventure film, and the fifth and final installment of the Highlander film series. Directed by Brett Leonard, this and the prior installment, Endgame (2000), follow the continuity of Highlander: The Series (1992-1998), continuing the story of immortal swordsman Duncan MacLeod, with actor Adrian Paul reprising his role from the series and Endgame. It is the only Highlander film not to feature the original protagonist, Connor MacLeod. Taking place in a future version of Earth that is largely violent and chaotic, the story depicts Duncan and allies seeking out an energy well that may be the "Source of Immortality".

The Source is the only Highlander film not theatrically released in North America. Instead, it was broadcast on the Sci-Fi Channel on September 15, 2007. Originally intended as the first of a planned trilogy of Sci-Fi Channel original movies, no further sequels have been planned due to overwhelming negative response. At the 2009 Highlander Worldwide Convention, TV series producer David Abramowitz referred to The Source as a "bad dream" Duncan had.