The Justice League actress, 31, looked glamorous in a long beaded dress with fringe on the bottom, which she accessorized with a beaded purse and ivory heels.
The 46-year-old Tesla and SpaceX founder was also dressed up for the occasion, wearing a black suit with a white button-down shirt.
The pair — who were first linked together in 2016 — called it quits again in February, after briefly rekindling their relationship.
“Elon decided it was time to end it and Amber agreed. They both still care deeply for each other but the timing wasn’t right,” a source close to the couple told PEOPLE at the time.
The duo first broke up because of their increasingly busy schedules in August of last year.
Heard and Musk were first romantically linked in 2016 as each was weathering a public breakup: Heard and actor Johnny Depp finalized their divorce in January, while Musk and Westworld actress Talulah Riley got divorced for the second time in early 2015.
In a story published three months after their first breakup, Musk told Rolling Stone that Heard was the driving force in their split.
“Well, she broke up with me more than I broke up with her, I think,” he explained. “I was really in love, and it hurt bad.”