Sam Puckett is a street-smart teenager who is a certified master at fighting her way out of any situation. Cat Valentine is a sweet, caring adolescent who has a knack for getting herself into sticky situations. When Sam makes her way to Los Angeles, the two meet and quickly become friends and roommates. After finding themselves looking after some younger kids, the teens decide to start Sam & Cat's Super Rockin' Fun-Time Babysitting Service to earn some extra cash for fun and adventures. The business is boosted by their young neighbor, Dice, who knows all of the building's tenants and can get people pretty much anything, including baby-sitting clients, and he has Sam and Cat fully covered. Cat's young-at-heart grandmother, Nona, is also around whenever the girls need her, even though her new life at Elderly Acres keeps her busy. Naturally, the baby-sitting venture results in wacky adventures for the girls.