Big B (short form of Big Brother) is a 2007 Indian Malayalam-language neo-noir action thriller film co-written and directed by Amal Neerad. It stars Mammootty in the title role, alongside an ensemble cast including Manoj K. Jayan, Bala, Sumit Naval, Mamtha Mohandas, Nafisa Ali, Pasupathy, Lena, Maniyanpilla Raju, Shereveer Vakil, Vinayakan, Innocent and Vijayaraghavan in supporting roles. The cinematography was done by Sameer Thahir, while the soundtrack and background score were composed by Alphonse Joseph and Gopi Sundar.

Even though it was a scene by scene copy of the 2005 Hollywood film Four Brothers, Big B is considered as a pathbreaking film in the history of Malayalam cinema. Big B introduced a new style of filmmaking and has later attained a huge cult following.