"Mrs. PENAVEGA," Vega tweeted on Saturday. The couple said "I do" at the Grand Velas Riviera Nayarit in Puerto Vallarta, Mexico.
Vega, 25, and Pena, 24, announced their engagement in September. The Big Time Rush star popped the question during a road trip and then shared a picture of the ring on Instagram.
This is the second marriage for Vega, who split from producer Sean Cove in July 2012 after two years of marriage. Best known for her role in Spy Kids, Vega will next guest-star on The Tomorrow People.