No Ordinary Family actor Collins will play Benjamin Hathaway, who served as Commander-in-chief prior to the alien invasion, TV Guide reports.
Hathaway - who will debut in the sci-fi drama's upcoming third season - has now been forced into taking on Earth's invaders in direct combat and is eager to meet Tom Mason (Noah Wyle) and his fellow rebels in the 2nd Mass.
Collins, expected to first appear in the season's fourth episode, has appeared in such films as 2006's Blood Diamond, 1979's Star Trek: The Motion Picture and 1976's All the President's Men. His past television roles include stints on The Office, Private Practice and 7th Heaven.
Falling Skies - which also stars Moon Bloodgood and Will Patton - was officially picked up for a third ten-part season in July.
The series will return to TNT in the US and FX in the UK in 2013.
> Noah Wyle Falling Skies season two Q&A: 'It's a fight to the finish'
Watch a clip from Falling Skies below: