The couple broke up in 2009, but it looks like they're still on speaking terms.
The actress walked up to Jonas, 24, who was sitting alone at a table, and the two looked friendly as they chatted for about 15 minutes, E! Online reported.
Belle wore a halter gown with a plunging neckline and tiered skirt to the event. Jonas had on a classic black tuxedo.
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Camilla Belle ran into her ex-boyfriend Joe Jonas Thursday night at the gala opening of the Wallis Annenberg Center for the Performing Arts in Beverly Hills.
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