Big Deal on Madonna Street (Italian: I soliti ignoti; released as Persons Unknown in the UK) is a 1958 Italian comedy caper film directed by Mario Monicelli. Regarded as one of the masterpieces of Italian cinema, the film received an Academy Award nomination for Best Foreign Language Film.

The plot revolves around a group of small-time thieves attempting to burglarize a pawn shop in Rome, resulting in a series of comedic mishaps. The main characters, portrayed by Vittorio Gassman, Renato Salvatori, Carlo Pisacane, Tiberio Murgia, and Marcello Mastroianni, collectively navigate the pitfalls of their ill-fated heist. The film contributed significantly to the careers of Gassman and Mastroianni, with the former breaking into comedic roles previously considered unsuitable for him.

Claudia Cardinale makes a minor appearance in the film, playing a chaste Sicilian girl constrained by her overbearing brother, portrayed by Murgia. Cardinale would later achieve fame for her subsequent work. The film's breezy jazz score by composer Piero Umiliani is also noteworthy, contributing to the development of the jazz soundtracks characteristic of European films in the 1960s and 1970s.

Initially doubtful about the film's potential success, the producers strategically featured the renowned comedian Totò on the original poster to generate audience intrigue. Despite being cast for comic relief, Totò's character opts to serve as a consultant to the heist gang instead of directly joining them.

In 2008, Big Deal on Madonna Street was included in the Italian Ministry of Cultural Heritage's list of 100 Italian films to be saved, acknowledging its impact on the collective memory of the country between 1942 and 1978.