The Lost Leonardo is an internationally co-produced documentary film directed by Andreas Koefoed, released in 2021. It follows the discovery and successive sales of the painting the Salvator Mundi, allegedly a work by Leonardo da Vinci, an artist for whom there are only a few attributed works in existence. The film chronicles the dramatic increases in the painting's value from its original purchase in 2005 for $1,175 to its auction in 2017 for $450 million, when it became the most expensive artwork ever sold. The use of high-end artwork for hiding wealth, as well as the conflicts created by large commissions and other economic incentives, are explored in the film. It includes interviews with leading art experts and art critics on issues regarding the provenance and authenticity of the work.

Production was announced in late 2019 following the success of Ben Lewis's book The Last Leonardo: The Secret Lives of the World’s Most Expensive Painting. The film had its world premiere at the Tribeca Film Festival on June 13, 2021, and was released in the United States on August 13, 2021, by Sony Pictures Classics and in the United Kingdom on September 10, 2021, by Dogwoof. The film was widely praised by critics for its content, pacing and the portrayal of the subject as a thriller. A French-made film on the topic called The Saviour for Sale was also released at the same time.

In October 2022, StudioCanal announced a plan to develop the film into a limited series with The Picture Company and Entertainment360.