The 45-year-old actor and 35-year-old actress, who play Jason Bourne and Nicky Parsons in the Bourne film series, turned heads on the red carpet at Caesars Palace.
Damon was accompanied by his wife, Luciana Barroso, who wore a sleeveless lilac gown with sequin detail. Stiles, meanwhile, stunned in a navy dress with botanical print.
Alicia Vikander and Tommy Lee Jones were also present at the event. The Ex Machina actress portrays Heather Lee, a CIA agent, while Jones plays Robert Dewey, the CIA director.
Damon and Stiles previously co-starred in The Bourne Identity, The Bourne Supremacy and The Bourne Ultimatum. Neither actor appeared in the fourth movie, The Bourne Legacy, which starred Jeremy Renner.
“I just have a lot of gratitude with this character,” Damon told KTNV at the premiere. “Jason Bourne changed my entire career … I look at my life now, and I make these movies, and I love what I do, and you know, a lot of that is because of this character.”
Jason Bourne opens in theaters July 29.