Leighton Marissa Meester (born April 9, 1986) is an American actress, singer, songwriter, and model. She is known mostly for her starring role as Blair Waldorf on the television series Gossip Girl (2007–2012). She has also appeared in the films Killer Movie (2008), Country Strong (2010), The Roommate (2011), Monte Carlo (2011), The Oranges (2011), and The Judge (2014). Meester made her Broadway debut in Of Mice and Men (2014).

In addition to acting, Meester has also ventured into music. In 2009, she featured on Cobra Starship's "Good Girls Go Bad" which charted within the top-ten of the Billboard Hot 100, and released her first single "Somebody to Love" under Universal Republic. Her second single "Your Love's a Drug" was released in 2011. Meester has also recorded songs for various soundtracks. Her debut album, Heartstrings, was independently released in 2014. She has also modeled, having been the face of brands such as Jimmy Choo, Herbal Essences, and Vera Wang.