The filmmaker’s wife, actress Emmanuelle Seigner, picked up the award on Saturday night.
Todd Phillips' Joker, starring American actor Joaquin Phoenix, grabbed the festival's top prize, the Golden Lion for Best Film.
Polanski’s An Officer and a Spy also claimed the International Federation of Film Critics (FIPRESCI) prize at the Venice festival.
Meanwhile, Polish director Jan Komasa took home the Europa Cinemas Label Award from this year’s Venice International Film Festival for his movie Corpus Christi, state news agency PAP reported.
Corpus Christi had its world premiere screening as part of the festival's Giornate degli Autori, or Venice Days, section last week.
The 76th Venice Film Festival, the world's oldest film festival, was held in the Italian city from August 28 to September 7.
Roman Polanski. Photo: EPA/JULIEN DE ROSA
Polanski, who was convicted of statutory rape in the United States in 1978, was last year expelled from the Academy of Motion Picture Arts and Sciences.
Polanski, now 86, fled the United States in February 1978, shortly before being sentenced for unlawful sex with a 13-year-old girl. He settled in Paris, where he has been chiefly based ever since.
He was arrested in 2009 while entering Switzerland to receive a prize at the Zurich Film Festival, as a US request for his extradition had been freshly submitted. However, the Swiss authorities ultimately backed down after keeping Polanski under house arrest for several months.
The director returned to France, but he has since visited Poland, where he grew up in a secular Jewish family in the historic city of Kraków.