Mynydd Mawr (Welsh for big mountain) is a mountain in North Wales.
Mynydd Mawr may also refer to: Llanarmon Mynydd Mawr, an isolated rural parish in Powys, Wales Llanelli and Mynydd Mawr Railway, a heritage railway aiming to re-instate the Llanelly and Mynydd Mawr Railway that closed in 1989 Llanelly and Mynydd Mawr Railway Ras Mynydd Mawr, an annual running race from Y Fron up the hill Mynydd Mawr Mynydd Mawr, a 160 metre hill near Aberdaron