The season upgrades previous supporting characters cast members such as Richard Woolsey (from Stargate SG-1) and Jennifer Keller.

The Wraith primary goal is to gather a fleet to invade Atlantis and find their new "feeding ground", Earth.

Season five regular cast members include Joe Flanigan, Rachel Luttrell, Jason Momoa, Jewel Staite, Robert Picardo, and David Hewlett.

Robert Picardo joined the permanent cast, with his character, Richard Woolsey, assuming command of Atlantis.

[4] The remainder of the season five regular cast comprised Joe Flanigan, Rachel Luttrell, Jason Momoa, and David Hewlett.