Ronin is a 1998 American action thriller film directed by John Frankenheimer and written by John David Zeik and David Mamet, under the pseudonym Richard Weisz. It stars an ensemble cast consisting of Robert De Niro, Jean Reno, Natascha McElhone, Stellan Skarsgård, Sean Bean, and Jonathan Pryce. The film is about a team of former special operatives hired to steal a mysterious, heavily guarded briefcase while navigating a maze of shifting loyalties. The film was praised for its realistic car chases in Nice and Paris.

Frankenheimer signed to direct Zeik's screenplay, which Mamet rewrote to expand De Niro's role and develop plot details, in 1997. The film was photographed by Robert Fraisse in his native France from November 3, 1997, to March 3, 1998. Professional racing car drivers coordinated and performed the vehicle stunts, and Elia Cmiral scored the film, his first for a major studio.

Ronin premiered at the 1998 Venice Film Festival before its general release on September 25. Critics were generally positive about the film's action, casting, and technical aspects, while the plot attracted criticism. The film underperformed at the box office, grossing $70.7 million on a $55 million budget. Ronin, Frankenheimer's last well-received feature film, was considered to be a return to form for the director. Film critic and historian Stephen Prince called the film Frankenheimer's "end-of-career masterpiece". The car chases, which were favorably compared with those in Bullitt and The French Connection, were included on several media outlets' lists as among the best depicted on film.