The announcement coincides with a Comic-Con panel for the show, where executive producer Remi Aubuchon and stars Noah Wyle, Moon Bloodgood and Will Patton are to discuss the current season with fans.
The network has ordered ten more episodes of the series to be screened in 2013.
The Steven Spielberg-produced alien drama chronicles the aftermath of an extra-terrestrial attack that has left much of the world incapacitated.
The show was rumoured to have secured renewal last month, as it has proved popular with viewers overseas as well in the US, where it is one of the highest rated cable dramas during the summer season.
Michael Wright, head of programming for TNT, said of the announcement: "Falling Skies is television storytelling at its very best, a powerful drama that's told on both an epic scale and on a deeply personal level.
"We can't wait to see what DreamWorks Television and Falling Skies' terrific production team and cast members have in store for season three."
The second season of Falling Skies is currently airing on TNT in the US, and FX in the UK.
Watch the UK trailer for Falling Skies below: