Sir William James Bailhache (born 24 June 1953) is a Jersey lawyer who was sworn in as Bailiff of Jersey on 29 January 2015. He has announced his retirement will be in October, 2019. He is the brother of Sir Philip Bailhache who previously served as Bailiff.
He was the island's Deputy Bailiff from 2 November 2009 until he was sworn in as Bailiff on 29 February 2015. He has also held the position of Her Majesty's Attorney General in Jersey for almost 10 years.