(William Bailey, Baily, or Bayly; died 1664) was an Anglican clergyman who served in the Church of Ireland as Bishop of Clonfert and Kilmacduagh from 1644 to 1664.

Born in Scotland, he was named after his father, William Bailie, a native of Ayrshire.

[1] He and his family were driven out of Scotland by the Covenanters, and fled to Ireland, where his father was granted the lands of Toneregie (now Tandragee) in County Cavan by King James I in 1610.

Little is known about his wife, but it is certain that they had a daughter Jane, who married James Hamilton of Coroneary and had issue.

From the Rolls of Chancery, 18–20 Charles I, it appears that Dr Bailie had been designed for the see of Kilmore, upon Bishop Bedell's death; for there is a revocation of several letters patent made to him, dated 3 March 1643-4.