"Hit 'em Up Style (Oops!)" is the debut single by American R&B singer Blu Cantrell, written and produced by Dallas Austin and featured on Cantrell's debut album, So Blu (2001). The lyrics propose that women should take revenge on cheating men by draining them of their available assets, both monetary assets and property. Cantrell has said that she did not particularly care for the song artistically, but the bitter feelings she was experiencing at the time led her to include it on the album anyway.
"Hit 'em Up Style (Oops!)" became Cantrell's most successful single in the U.S. to date and her only single to enter the top forty of the Billboard Hot 100 so far, peaking at number two (where it spent two consecutive weeks) on the issue date of July 21, 2001 behind Usher's "U Remind Me" (Cantrell would appear on the remix of the song). It enjoyed similar success in Europe and Oceania.
"Hit 'em Up Style (Oops!)" was also featured on European, Australian, and Japanese versions of Cantrell's second album Bittersweet as well as the 2004 game, Donkey Konga 2 and another appearance in another video game, Just Dance 4.