Isla Lang Fisher (born on February 3 1976 in Muscat, Oman) is an Australian actress, model and author.

She played Shannon Reed, a fiery, opinionated teenager, on Australian soap Home and Away from 1994-1997. During this time, she wrote two books, Seduced by Fame, about an ambitious aspiring actress whose dreams come true when she wins a role on her favourite show, and Bewitched, about a naive ballerina who searches for her father and falls in love for the first time. Most recently, she starred in Wedding Crashers with Owen Wilson, Vince Vaughn, and Rachel McAdams, and has won vast praise for her comedic performance in the movie.

She is the fiancee of British comedian Sacha Baron Cohen (Ali G). Of Scottish descent, Fisher resides in England.

She was officially crowned 1000th guest on Rove Live, a popular Australian talk show, on August 2, 2005. She was visiting the show to promote the film Wedding Crashers with co-star Owen Wilson. She was the first to enter from backstage, therefore winning the title by a mere two metres.