Flame & Citron (Danish: Flammen & Citronen) is a 2008 historical drama film co-written and directed by the Danish director Ole Christian Madsen. The film, a fictionalized account based on historical events, stars Thure Lindhardt and Mads Mikkelsen as two Danish resistance movement fighters nicknamed Flammen and Citronen, during the Nazi occupation of Denmark in World War II. Attracted by the story of the pair since he was twelve, Madsen spent eight years along with co-writer Lars K. Andersen researching historical archives to produce it.

Madsen's idea was to bring attention to the story of Flammen and Citronen as he felt it had been neglected or misrepresented. The most expensive Danish film produced to that date, it was co-produced by German companies because initially there was no interest in producing the film in Denmark. Portraying the protagonists as morally ambiguous characters, the director tried to depict war as a complicated experience that goes beyond a good versus evil dichotomy. With visual and narrative references borrowed from film noir and the French film Army of Shadows, Flame & Citron also explores themes of love, betrayal, and the emotional aspects of relationships.

The film was released in Denmark on 28 March 2008 to positive reviews. The most-watched film in the country that year, it was praised mostly for the actors' performances, dramatic style, and depiction of war and its moral dilemmas. Considered an art film by some critics, the film was compared, both favorably and negatively, to Army of Shadows and other war films; it also sparked a debate over its historical accuracy. Additionally, it was nominated for both domestic and international film awards, including the Robert Awards, the Bodil Awards, and the European Film Awards.