Jules Anton Deelder (24 November 1944 – 19 December 2019) was a Dutch poet, spoken word poet and writer. His poems cover topics such as life in the city of Rotterdam, drug use, and jazz. He was very passionate about the Dutch language and feared that European integration would cause smaller languages like Dutch to become a "folkloric" curiosity. He was 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 to record and perform his poetry. His prominent role in the cultural life of Rotterdam earned him the nickname "night mayor of Rotterdam."