A marching band is, in the broadest terms, a group of performers that consist of instrumental musicians and sometimes dance teams / color guard who generally perform outdoors and incorporate some type of marching (and possibly other movements) with their musical performance. Instrumentation typically includes brass, woodwinds, and percussion instruments. Most marching bands use some kind of uniform (often of a military style) that include the school or organization's name or symbol, shakos, pith helmets, feather plumes, gloves, and sometimes gauntlets, sashes, and/or capes.

Marching bands are generally categorized by function, size and by the style of show they perform. In addition to traditional parade performances, many marching bands also perform field shows at special events (such as football games) or at competitions. Increasingly, marching bands are performing indoor concerts (in addition to any "pep band" duties) that implement many of the songs, traditions, and flair from outside performances.