A show choir (previously known as a "swing choir") is a musical ensemble that combines choral singing with choreographed dance, often integrated into a narrative story or overarching theme.

Show choirs have been popularized by the American television show Glee but have a longer history dating back to glee clubs in London in the 18th century, musical theatre, music in the plays of William Shakespeare and the theatre of ancient Greece.

Show choirs sing music as a type of performing arts, for example as secondary school activities in the United States. They are typically co-curricular activity (part of a class or connected to the academic curriculum) or an extracurricular activity. Alternate examples include organizations formed outside of a school, such as community choirs that make use of students from multiple schools in the surrounding area. Though usually a high school activity, show choirs exist at all levels of school from elementary through the collegiate level.

Outside of the United States, show choirs can be found in countries such as Canada, Mexico, United Kingdom, Ireland, Philippines, and Argentina.

While there is no standard requirement for the number of performers or demographic of its students, a show choir typically consists of thirty to sixty singer/dancers. Factors like school size and/or director preferences may impact this number. Larger schools with more advanced programs may have more than one competitive show choir ensemble. Show choirs composed entirely of students of one gender usually compete in separate divisions from mixed-gender show choirs, with the exception of "open" divisions, where groups of different types compete against each other.

Show choir performers traditionally wear costumes, though the definition of what is considered a costume in this context is broad. Costumes range from conservative looks (such as formal tuxedos and ball gowns) to modern (tracksuits with name-brand sneakers) to avant-garde fashion (such as modern head-to-toe uniforms or revealing clothing). Additionally, many larger groups include two or more costumes in their show. Singer/dancers typically wear stage makeup and shoes conducive to dancing (called "character shoes").

Uniformity in look among performers is often an important characteristic of the genre. In most cases, there is consistency in costuming and makeup from person to person; this consistency extends to elements like hair, where singer/dancers will all style their hair in a visually consistent way.

The choir usually has a backup band (often called the "show band", "pit" or "combo" if it includes a horn section) providing instrumental music to accompany the singers' voices. Instrumentation selection often varies between choirs and even from one group's song selection to another, but a common show choir band consists of trumpets, trombone, alto/soprano sax, tenor sax, piano, and synthesizer, guitar, bass, auxiliary percussion, and a drum set. Bands may include other instruments such as violin or cello if their show requires it. The band is usually situated behind the performance area for the singer/dancers, but occasionally, a group will bring out members of the band onstage to accentuate thematic elements in the show.