Williams was joined by her sister, Venus Williams, and closest friends, including Ciara, Kelly Rowland, La La Anthony, Eva Longoria and songwriter Angie Beyince. The ladies were adorably dressed in poodle skirts, bandanas, wearing high ponytails and other 1950s attire.
A handful of the gals took to social media to share sweet and silly moments from the party.
"That's 1 Fly Mamma 2 Be In The Middle! ??#Girls @SerenaWilliams 50's Baby Shower. #ShakeRattleRoll2017," Ciara captioned a fabulous group pic!
A source close to Williams tells ET that the fun bash ended with an epic dance party.
"Val Vogt of the The VLV Group, who also planned Serena's bridal shower, planned a lively, detail oriented co-ed 1950s theme baby shower held at Nick's 50s Diner in West Palm Beach," the source says. "It was a small intimate crowd. Everyone dined on burgers, shakes, cherry pie a la mode, played games, crafted and ended the evening with an epic dance party -- limbo and all."
"Vogt had everyone surprise Serena by bringing a children's book and writing a message for the baby inside, among other personalized crafting stations set up throughout the diner," the source continues. "Serena loves a good themed party! All in all, both the parents-to-be and guests had a blast celebrating the baby on the way."