William was born in Leeds and most of his early childhood was spent living in Burley-in-Wharfedale where he attended Menston Junior School. After passing his 11+ exams he moved to Ilkley Grammar School at the age of 11 and remained there through Sixth Form before ultimately taking up a place at Rose Bruford College on the B.A.(Hons) Theatre Arts Course.
His family; mother -Hannah and father -Bill moved house to Ilkley just after William started at Ilkley Grammar School. William is the eldest of four children. His family, birth, surname was Brown and throughout his childhood and school years he was known as Billy Brown, but unfortunately he was unable to use this name professionally when he became a member of Equity (the Actors Union) in 1980, as a William Brown and a Billie Brown already existed. At this point he took the professional name of WILLIAM ILKLEY, using the town where he lived as his new surname!
William has four children; Oliver, Dominic, Adele and Abigail and two new grandchildren Amelia and Phoebe-Mae.
William now lives in East Yorkshire with his wife Sidonie and Abigail. He has been a life-long Bradford City supporter and is a current season ticket holder, attempting to get to most home games where he meets up with friends from schooldays!