Three Colours: Blue (French: Trois couleurs: Bleu, Polish: Trzy kolory: Niebieski) is a 1993 psychological drama film co-written and directed by Polish filmmaker Krzysztof Kieślowski. It is the first instalment in the Three Colours trilogy, themed on the French Revolutionary ideals of liberty, equality and fraternity, followed by White and Red (both 1994). According to Kieślowski, the subject of the film is liberty, specifically emotional liberty, rather than its social or political meaning.

Set in Paris, the film follows a woman named Julie (Juliette Binoche) whose husband and daughter are killed in a car accident. Suddenly freed from her familial bonds, she tries to isolate herself and live in seclusion from her former ties. However, she discovers that she cannot escape human connections.

Upon its release, Blue received widespread critical acclaim and won several accolades, including the Golden Lion and the Volpi Cup for Best Actress at the Venice Film Festival. It remains one of Kieślowski's most celebrated works. The male lead, Benoît Régent, died of an aneurysm at the age of 41 in October 1994, just one year after the film was released.