Sir John Brereton (1576-1629) was an English-born lawyer who held office in Ireland as Serjeant-at-law (Ireland). He was born in Ashley, Cheshire, one of the eight sons of George Brereton of Ashley Hall and Sybil Arderne, daughter of William Arderne of Timperley, near Altrincham. The Breretons were descended from Sir William Brereton, who was Earl Marshal of Ireland in the time of Henry VIII. John was baptised at the parish church in Bowdon on 20 June 1576. He attended Sidney Sussex College, Cambridge, of which he was later to be a generous benefactor. He practiced as an attorney for some years and was then called to the Bar at the Inner Temple in 1609. He moved to Ireland and was admitted to the King's Inn in 1613.