Longoria brought her husband, Jose Baston, while Wozniacki attended with her fiance, David Lee.
Entertainment Tonight reported Williams and Ohanian's daughter, 2-month-old Alexis Olympia, was also in attendance.
Williams and her baby girl took a private jet to New Orleans last week ahead of the nuptials.
Williams' longtime coach Patrick Mouratoglou was among those to congratulate Williams and Ohanian online.
"@serenawilliams I send you all my positive feelings for that very special day. I wish you a very happy wedding, a fantastic party and a full life of happiness with @alexisohanian," he wrote on Instagram.
Williams and Ohanian got engaged in December 2016, and welcomed Alexis Olympia in September.
The couple celebrated their rehearsal dinner Wednesday at Emiel Lagasse's restaurant Meril.
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