Paul Rudd, Steve Martin and Martin Short Mingle Ahead of Selena Gomez's Wedding

Selena Gomez's wedding to Benny Blanco will be as star-studded as it gets ... with some of her "Only Murders in the Building" co-stars Steve Martin, Martin Short and Paul Rudd confirmed to be supporting her on her special day!

Check out our gallery -- the actors all gathered Friday evening at Santa Barbara, California's luxury hillside hotel El Encanto for some mingling on the elegant patio before heading off to the rehearsal dinner.

All three actors look dapper, dressed in suits and smiling as they spoke among other well-dressed guests. Paul is even seen cracking up as he speaks to Steve at one point.

While she was not present, we know Selena's longtime bestie Taylor Swift is also in the area for the highly anticipated wedding. We caught her stepping off her private jet at the Santa Barbara airport Friday afternoon ... though we only saw a glimpse of her arm because she walked behind a wall of privacy umbrellas.

As we reported ... Selena and her better half are saying "I do" at a stunning private estate adorned with palm trees and lush vegetation in Montecito Saturday.