The Cylons are a cybernetic civilization at war with the Twelve Colonies of humanity in the Battlestar Galactica science fiction franchise, in the original 1978 & 1980 series, as well as the 2003 reimagining. In the 1978 series, the Cylons are also the race who created the robot Cylons.

The nature and origins of Cylons differ greatly between the two Galacticas. However both series feature Cylon Raiders, Cylon Basestars and Cylon Centurions.