Julius Anton (Jules) Deelder (born 24 November 1944 in Rotterdam) is a Dutch poet and writer. His poems cover topics such as life in the city of Rotterdam, drug use, and jazz. He is well-known in the Netherlands for his live performances and appearances in Dutch popular media. He collaborated with musicians and bands such as Herman Brood, Benjamin Herman and Bas van Lier to record and perform his poetry. His prominent role in the cultural life of Rotterdam earned him the nickname "nightly mayor of Rotterdam".