Fast & Furious (also known as Fast & Furious 4) is a 2009 action film directed by Justin Lin and written by Chris Morgan. It is the direct sequel to The Fast and the Furious and 2 Fast 2 Furious as well as the fourth installment in the Fast & Furious franchise. It stars Vin Diesel, Paul Walker, Michelle Rodriguez, and Jordana Brewster. In the film, Dominic Toretto (Diesel) and FBI agent Brian O'Conner (Walker) are forced to work together to avenge the murder of Toretto's lover Letty Ortiz (Rodriguez) and apprehend drug lord Arturo Braga (John Ortiz).

A fourth film was announced in July 2007, with the returns of Diesel, Walker, Rodriguez, and Brewster confirmed shortly thereafter. To account for the cast seeing absences from either of the previous two installments, the film was developed to place The Fast and the Furious: Tokyo Drift (2006) as occurring beyond the events of Fast & Furious, while the short film Los Bandoleros (2009) was produced and released. Principal photography began in February 2008 and concluded that July, with filming locations including Los Angeles and the Dominican Republic. Lin, Morgan, and composer Brian Tyler returned in their roles from Tokyo Drift. Fast & Furious is the first film to feature D-BOX motion. It was also the first film in the franchise to be produced by Diesel.

Fast & Furious premiered at the Gibson Amphitheatre in Los Angeles on March 12, 2009, and was released in the United States on April 3, by Universal Pictures. The film received mixed reviews from critics, with praise for reuniting the original cast and the action sequences, but criticism for its screenplay. It grossed over $360 million worldwide, exceeding expectations to become the then-highest-grossing film in the franchise. It also grossed $72.5 million worldwide during its opening weekend, which made it the highest-grossing worldwide spring weekend opening, until the release of Alice in Wonderland (2010). It was followed by Fast Five in 2011.