The third season of Stargate Atlantis, an American-Canadian television series, began airing on July 21, 2006 on the US-American Sci Fi Channel.

The series was developed by Brad Wright and Robert C. Cooper, who also served as executive producers.

Season three regular cast members include Joe Flanigan, Torri Higginson, Rachel Luttrell, Jason Momoa, Paul McGillion, and David Hewlett as Dr. Rodney McKay.

"No Man's Land" won a Gemini Award for "Best Visual Effects".

For "McKay and Mrs. Miller", writer Martin Gero was nominated for a Gemini Award in the category "Best Writing in a Dramatic Series".