Bill Treacher (born 4 June 1937) is a British actor.

He was born in London. After graduating from the prestigious Webber Douglas Academy of Dramatic Art, he made his West End debut in 1963 with the comedy Shout for Life at The Vaudeville Theatre. A string of successful West End roles followed before he moved into television drama, making guest appearances in a number of classic serials of the 1970s including Minder, The Sweeney, The Professionals, Dixon of Dock Green, Z Cars and The Agatha Christie Hour .

In 1985 he was the first actor to be cast in the BBC soap opera EastEnders, where he played the luckless Arthur Fowler for eleven years. He received much critical acclaim for the role, especially for his portrayal of his character's mental decline and subsequent nervous breakdown. He left the series in 1996 and has since made several films, most notably The Musketeer and Tale of the Mummy.

He is married to the Australian actress Katherine Kessey and they have two children, Jamie and Sophie.