Portrait of a Lady on Fire (French: Portrait de la jeune fille en feu, lit. 'Portrait of the Young Lady on Fire') is a 2019 French historical romantic drama film written and directed by Céline Sciamma, starring Noémie Merlant and Adèle Haenel. Set in France in the late 18th century, the film tells the story of a brief affair between two young women: an aristocrat and a painter commissioned to paint her portrait. It was Haenel's final film role before she retired from the French film industry in 2023.

Portrait of a Lady on Fire was selected to compete for the Palme d'Or at the 2019 Cannes Film Festival. The film won the Queer Palm at Cannes, becoming the first film directed by a woman to win the award. Sciamma also won the award for Best Screenplay at Cannes. The film was theatrically released in France on 18 September 2019.

It was nominated for Independent Spirit Awards, Critics' Choice Awards and Golden Globe Awards for Best Foreign Language Film and was chosen by the National Board of Review as one of the top five foreign language films of 2019. The film was one of three shortlisted by the French Ministry of Culture to be France's submission to the 92nd Academy Awards for Best International Feature Film.

Portrait of a Lady on Fire was voted the 30th greatest film of all time in the Sight & Sound 2022 critics' poll. It has also been considered to be one of the best films of 2019 and of all time.