An Officer and a Spy (French: J'accuse) is a 2019 historical drama film directed by Roman Polanski about the Dreyfus affair, with a screenplay by Polanski and Robert Harris based on Harris's 2013 novel of the same name. The name J'accuse has its origins in Émile Zola's article in l'Aurore in January 1898 in which the famous author accused many people of France of continuing to support the increasingly blatantly erroneous accusations against Dreyfus.

The film had its premiere at the 76th Venice International Film Festival on 30 August 2019, winning the Grand Jury Prize and the FIPRESCI Prize. It received twelve nominations for the 45th César Awards, the most nominations of any eligible film, and eventually won the awards for Best Adaptation, Best Costume Design, and Best Director. The film was also nominated in four categories at the 32nd European Film Awards, including for Best Film, Best Director, Best Actor, and Best Screenwriter, ultimately winning none. It received David di Donatello and Polish Film Awards nominations as Best Foreign and Best European film respectively. It became a box-office bomb, grossing $18.9 million worldwide against a production budget of $24 million.