Hair today, gone tomorrow — literally. The following 20 celebs have had hair transformations like no other. Check them out.

Lisa Rinna swapped the signature bob she made famous during her eight seasons on RHOBH for a curly blonde pixie at the premiere of RuPaul’s new movie Stop! That! Train!, in which she has a cameo.

Jessica Chastain styled her hair in an unexpected updo on May 20 after recently unveiling a blonde bob hair transformation. See the look, here.

And understandably, it can be daunting to undergo a major hair transformation. There are maintenance costs, makeup routine considerations, and the biggest, most basic question of all: Will it look good?

Paris Hilton swapped her usual blonde locks for a brunette hair transformation complete with side bangs as she walked the runway at the Gucci fashion show May 16.

Weeks ahead of her Broadway debut in "Every Brilliant Thing," "Law & Order: SVU" star Mariska Hargitay showed off a dramatic hair transformation.

The 45-year-old heiress walked in the Gucci fashion snow in Times Square

Kate Middleton's hair in a short, slightly bobbed style is something we don't see often as Prince William's wife loves a long blow-dry. But in 2017, at Wimbledon, she had a long bob, and it looked stunning.