Three Colours: Blue (French: Trois couleurs: Bleu, Polish: Trzy kolory: Niebieski) is a 1993 drama film directed and co-written by Polish filmmaker Krzysztof Kieślowski. It is the first of three films that make up the Three Colours trilogy, themed on the French Revolutionary ideals of liberty, equality, and fraternity, followed by White and Red. 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 whose husband and child are killed in a car accident. Suddenly freed from her familial bonds, she tries to isolate herself from everything and live in seclusion from her former ties. However, she discovers that she cannot escape human connections.

Upon its release, Blue received 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.