The new show - which stars Andre Braugher and Scott Speedman - follows the crew of a rogue nuclear submarine and will premiere on September 27 on ABC.
Autumn Reeser also stars as series regular Kylie, with Gaston now cast as her father - an influential Washington power broker.
The 49-year-old actor will appear in multiple episodes of Last Resort's first season, according to Deadline.
Gaston previously played Detective Mike Costello on CBS drama Unforgettable, but was dropped from the show as part of a revamp for its forthcoming second season.
He has also appeared in Damages, The Mentalist and 2010 film blockbuster Inception.
> Hostel star Jay Hernandez joins new ABC drama Last Resort
> Last Resort adds The Shield actor Jay Karnes
Watch a trailer for Last Resort below: