A boy band is a musical act consisting of at least three young men who typically sing in harmony and perform choreographed dances. The members of a boy band usually do not play instruments as part of their performance, a fact which distinguishes the boy band from a regular band. Boy bands typically fall into pop, hip hop, or R&B genres, and their fans are usually young people, mostly girls.

Boy bands are often criticized for being fabricated by producers — which the majority are — and for having essentially talentless members chosen only for their looks. However, most boy band members are talented singers and dancers, many of whom can also play an instrument, and many of whom pursue solo careers in music after the boy band dissolves. While boy bands are notorious for lip-syncing during performances and for using session singers on studio recordings, it is not economical for a producer to invest in an entire group of band members who cannot sing.

A boy band has a short shelf life almost by definition; boys only remain boys for so long, and as fans age past the demographic boy bands are meant to appeal to, they commonly lose interest. This fact, along with the fact that most boy bands do not form on their own or write their own music, has contributed to the popular image of the boy band as not being a genuine band.

Whether or not one respects boy bands, their popularity, though short-lived, is undeniable. It is common for the members of a boy band to be portrayed as different types, such as the "bad boy" or the "baby," in order to appeal to a wider population. Boy bands often have a much larger following than other types of bands, though they can rarely sustain for over five years or so. Some boy bands, however, such as the Jackson 5, survived well past this mark.

New Kids on the Block, the 1980s brainchild of music producer Maurice Starr, is often considered the first boy band to be recognized as such, but the trend is actually older. The Jackson 5 debuted in 1962, for example, and the Puerto Rican boy band Menudo debuted in 1977. The boy band has its roots in even older forms of music, including a cappella harmony acts and gospel music, both of which sometimes incorporate choreography.