Now That's What I Call Music! 51 was released on August 5, 2014. The album is the fifty-first edition of the (U.S.) Now series. It peaked at number 3 and 4 on the Billboard 200 and has been certified 2x Platinum by the RIAA. The compilation includes two songs which reached the Billboard Hot 100: "Rude" and "Fancy".
The cover is inspired by the NOW 90 UK cover released in 2015, with a different color scheme.