 Winnington was the second, but eldest surviving, son of Salwey Winnington of Stanford Court, Member of Parliament for Bewdley, and his wife Anne Foley, daughter of Thomas Foley, MP, of Witley Court, Worcestershire.He was grandson of Sir Francis Winnington, who had been Solicitor General in the 1670s.He was educated at Westminster School and matriculated at Christ Church, Oxford in 1713.