Julius Ernst Wilhelm Fucík (1872 – 1916) was a Czech composer and conductor of military bands.  Fucík spent most of his life as the leader of military brass bands. He was a prolific composer, with over 300 marches, polkas and waltzes to his name. As most of his work was for military bands he is sometimes known as the "Bohemian Sousa".

Today his marches are still played as patriotic music in the Czech Republic. However his world wide reputation rests on one work, his opus 68 march the Entrance of the Gladiators (Vjezd gladiátoru), which is universally recognized as the theme tune of clowns in a circus. Despite being so widely known, the tune's original name and composer are relatively obscure. Also his lesser known Florentiner March is a staple march for many ensembles.