Trewern is a village in Montgomeryshire, Wales.
Trewern may also refer to:
Trewern, Radnorshire, a village in Radnorshire, Wales Trewern and Gwaethla, a former community in Radnorshire, Wales Trewern Hall or Trewern Farmhouse, a country house in Montgomeryshire, Wales Trewern House, one of the Grade II* listed buildings in Powys, Wales Trewern Mansion, in the village Llanddewi Velfrey, Pembrokeshire, Wales Trewern United F.C., a football club based in Montgomeryshire, Wales
See also E. P. Trewern (1895-1959), architect Trewen, a hamlet and a civil parish in east Cornwall, England