Jessica and her fiancé Eric Johnson were among the A-list stars attending the top-secret ceremony held at the home of the groom's good friend and former Scrubs costar, Zach Braff.
Cobb and Faison became engaged in 2011.
She and Simpson have been best pals since meeting in 1997, and Cobb recently told iVillage.com, "She’s just in the happiest place I’ve ever seen her in. Even on her worst day, she’s still happy with her life. If things get hard or rough, she’s just like, "Well, I’ve got Maxwell and I’ve got Eric. It’s never gonna be that bad."
Simpson, who is pregnant with her second child, and Johnson have yet to set their own wedding date.