Obsessed is a 2009 American psychological thriller film directed by Steve Shill and written by David Loughery. Starring Idris Elba, Beyoncé, and Ali Larter, the film follows Lisa Sheridan (Larter), an office temp who develops unrequited feelings for her boss, Derek Charles (Elba), and repeatedly attempts to seduce him. Derek's wife, Sharon (Beyoncé), learns of Lisa's escalating behavior and suspects her husband is having an affair.

Idrissa Akuna Elba is an English actor, rapper, singer, and DJ. An alumnus of the National Youth Music Theatre in London, he is known for roles including Stringer Bell in the HBO series The Wire (2002–2004), DCI John Luther in the BBC One series Luther (2010–2019), and Nelson Mandela in the biographical film Mandela: Long Walk to Freedom (2013). For Luther, he received four nominations each for a Golden Globe Award for Best Actor and a Primetime Emmy Award for Outstanding Lead Actor, winning one of the former.