Robbie stars as stereotypical Barbie with Gosling as Ken. America Ferrera and Ariana Greenblatt are humans, Gloria and Sasha, who somehow get sucked into Barbie's orbit and help her on her journey. McKinnon, Shipp, Mackey, Rae, Nef, Rooney, Cruz Kayne, Coughlan, and Arya are all Barbies. Simu Liu, Scott Evans, Ncuti Gatwa, and Kingsley Ben-Adir are all Kens. Michael Cera and Emerald Fennell are friends of Barbie and Ken, Allan and Midge. Ferrell's character is the CEO of Mattel, and Connor Swindells and Jamie Demetriou play two of his employees. Helen Mirren serves as the story's narrator. John Cena plays a mermaid version of Ken, and Rhea Perlman plays Barbie inventor Ruth Handler. Rob Brydon plays Sugar Daddy Ken and Tom Stourton plays Earring Magic Ken.
As for other weird Barbie variations, Mette Narrative plays Barbie Video Girl, Marisa Abela plays Teen Talk Barbie, and Lucy Boynton plays Proust Barbie. Erica Ford plays Skipper and Hannah Khalique-Brown plays "Growing Up" Skipper. Costume designer Ann Roth plays the woman on the bench. There's also a cameo by Rob Brydon as Sugar Daddy Ken.