Swing music, also known as swing jazz, is a form of jazz music that developed in the early 1930s and had solidified as a distinctive style by 1935 in the United States. Swing uses a strong anchoring rhythm section which supports a lead section that can include brass instruments, including trumpets and trombones, woodwinds including saxophones and clarinets or stringed instruments including violin and guitar; medium to fast tempos; and a "lilting" swing time rhythm. Swing bands usually featured soloists who would improvise a new melody over the arrangement. The danceable swing style of bandleaders such as Benny Goodman and Count Basie was the dominant form of American popular music from 1935 to 1945.

The verb "to swing" is also used as a term of praise for playing that has a strong rhythmic "groove" or drive.