Donning a giant blond wig and a curve-hugging black ensemble, the 36-year-old actress looked pitch perfect as the iconic good-girl-gone-bad, while Johnson could have given 1970s-era John Travolta a run for his money in a black leather jacket and epic greaser garb.
"Danny Zuko and 'Sandra Double Dee,'" Simpson captioned a photo of the pair she posted to Instagram on Monday.
In true rebellious spirit, the cute couple didn’t force their 4-year-old daughter Maxwell or 3-year-old son Ace to match the Grease theme, but instead gave them free reign over what they wanted to wear -- so naturally they opted to dress as exotic wildlife.
"When your kids are old enough to choose their own costumes," Simpson captioned an adorable snapshot of her photogenic family "#HappyHalloween from my parrot & octopus!"
Maxwell looked adorable as the brightly feathered fowl, while Ace rocked a colorful cephalopod ensemble.