The characters from the Canadian-American military science fiction television series Stargate Atlantis were created by Brad Wright and Robert C. Cooper. The series follows the adventures of a human expedition to the lost city of Atlantis in the Pegasus Galaxy. The Stargate has brought humanity into contact with other cultures, including new and powerful enemies: the Wraith, the Genii, and later the Asurans and a lost tribe of Asgard, all while trying to uncover the secrets the Ancients left behind.
Stargate Atlantis has a small cast, amounting to ten main cast actors over its five-season run. Most characters are introduced in outgoing expeditions outside the city of Atlantis.