Mahel de Hereford was a holder of the feudal lordships of Brecon and Abergavenny in the Welsh Marches in the mid 12th century.
Mahel de Hereford was a younger son of Miles de Gloucester, 1st Earl of Hereford and his wife Sibyl of Neufmarche, daughter of Bernard de Neufmarche, Lord of Brecon.
His brothers were Walter de Hereford and William de Hereford.
Mahel held the posts of King's Constable in the region and succeeded to the lordships of Brecon and Abergavenny in 1163. In 1163 / 1164 he attended the Council of Clarendon.
He died circa 1164, without issue, and is buried at Llanthony Priory, Monmouthshire.