MMMBop is a song written and performed by the American group Hanson. It originally appeared on the album MMMBop as a ballad, but became a hit single when turned into a bubblegum pop song for the album Middle of Nowhere.

"MMMBop" was a number one hit worldwide, thanks to heavy promotion and radio play by Hanson's record label, Mercury Records. It was also one of the biggest debut singles of all time, for instance in Australia it became only the second debut single to enter the ARIA charts at the number one position. It was voted as the best single of the year in The Village Voice Pazz & Jop critics poll.

The song's lyrics talk about the transient and unpredictable nature of friendship, referring to how friendships come and go in a "MMMBop", meaning a short space of time. The song therefore urges listeners to "hang on to the ones who really care, in the end they'll be the only ones there".