Isla Lang Fisher (; born 3 February 1976) is an Australian actress. Born in Muscat, Oman to Scottish parents with whom she moved to Australia during her childhood, she began appearing in television commercials before portraying, aged 18 to 21, the character of Shannon Reed in Home and Away, an Australian television soap opera. Fisher moved to Hollywood with a supporting role in the comedy horror film Scooby-Doo (2002) and has since starred in films such as Wedding Crashers (2005), Wedding Daze (2006), Confessions of a Shopaholic (2009), Bachelorette (2012), The Great Gatsby (2013), Now You See Me (2013), and Nocturnal Animals (2016). Her other credits include I Heart Huckabees (2004), Definitely, Maybe (2008), Keeping Up with the Joneses (2016), Tag (2018), and The Beach Bum (2019), in addition to voice roles in animated films such as Horton Hears a Who! (2008), Rango (2011), Rise of the Guardians (2012), Back to the Outback (2021), and Dog Man (2025). Fisher had a recurring role on the fourth and fifth seasons of the sitcom Arrested Development (2013–2019) and has starred in the comedy drama series Wolf Like Me since 2022. She has authored two young adult novels and the Marge in Charge book series. From 2010 to 2025, she was married to English comedian Sacha Baron Cohen, with whom she has three children.