Werner of Eppstein (c. 1225 - 2 April 1284) was the Archbishop of Mainz from 1259 until 1284. Werner was a son of Count Gerard II of Eppstein, and in childhood his parents decided he was to have a church life. He was educated in Mainz and worked as a clergyman. As two members of his family were archbishops of Mainz (Siegfried II and Siegfried III), Werner quickly rose through the ranks of the church. He became the provost of Mariagreden in 1248, the provost of St Peter in 1249, and the provost of St Peter and Alexander in 1257. The last two carried an archdeaconate, making Werner powerful in the archdiocese.