The 44-year-old actor and 38-year-old actress portray Mark Watney and Melissa Lewis in the sci-fi drama, respectively. Kristen Wiig, Kate Mara and Chiwetel Ejiofor, who play Annie Montrose, Beth Johanssen and Vincent Kapoor, were also in attendance.
Damon sported a navy jacket with sapphire tie, while Ejiofor looked dapper in a grey, plaid blazer. Chastain stunned in a black gown with embellished overlay, while Wiig wore a short frock with embroidered floral detail. Mara turned heads in an ivory dress with asymmetrical hem.
The Martian is based on the Andy Weir novel of the same name, and opens in theaters Oct. 2. Alien director Ridley Scott helmed the movie, which sees Damon's character attempt to survive on Mars long enough for his crew to come to the rescue.
Damon last appeared in the sci-fi film Interstellar, and is also scheduled for The Great Wall with Pedro Pascal and a new Jason Bourne movie. Chastain is slated for Crimson Peak with Tom Hiddleston and Snow White prequel The Huntsman with Chris Hemsworth.