Iranian filmmaker Mohammad Rasoulof took the top prize from a jury headed by actress Uma Thurman, beating a diverse international selection of 17 other titles to the honor, according to ISNA.
The award was presented by this year’s Un Certain Regard jury president Uma Thurman, heading a panel that also included filmmakers Joachim Lafosse and Mohamed Diab, actor Reda Kateb and Karlovy Vary festival director Karel Och.
"A Man of Integrity” is a tense drama about a man persecuted by powerful economic and political forces who refuses to bribe his way out of trouble.
Rasoulof's win comes three months after Asghar Farhadi won the Best Foreign Language Film Oscar for "The Salesman", also shot in Iran, and recognizes him as a major force in international cinema.
Variety called "A Man of Integrity" "a tense, enraging drama about corruption and injustice.
"Un Certain Regard", a separate section from the main contest at Cannes, recognizes younger talent and innovative filmmaking.