John Martin Tchicai (/tʃɪˈkaɪ/ chih-KYE; April 28, 1936 – October 8, 2012) was a Danish free jazz saxophonist and composer.

Tchicai was born in Copenhagen, Denmark, to a Danish mother and a Congolese father. The family moved to Aarhus, where he studied violin in his youth, and in his mid-teens began playing clarinet and alto saxophone, focusing on the latter. By the late 1950s he was traveling around northern Europe, playing with many musicians. In 1962, he met trumpeter Bill Dixon and saxophonist Archie Shepp at a festival in Helsinki. At their suggestion, he moved to New York City the following year, and went on to participate in the October Revolution in Jazz and join the New York Contemporary Five and the New York Art Quartet. He also played on a number of influential free jazz recordings, including Shepp’s Four for Trane, Albert Ayler‘s New York Eye and Ear Control, John Coltrane‘s Ascension, and the Jazz Composer’s Orchestra‘s Communication.