Castelnuovo was born the youngest of three boys, in Lecco, Lombardy into a humble family. After being a house painter, a mechanic and a workman, at a young age he moved to Milan where he started working as a sales agent, and at the same time he enrolled in the acting school of the Piccolo Teatro in Milan. He became a father for the first time to his son Lorenzo when he married Danila Trebbi, an Italian actress.
Career
In 1957, Castelnuovo debuted as a mime in the RAIchildren's television showZurli il mago del giovedì. He landed a small part in the crimemystery filmUn maledetto imbroglio, directed by Pietro Germi, and played supporting roles in films, including the dramas The Hunchback of Rome, directed by Carlo Lizzani; and Rocco and His Brothers, directed by Luchino Visconti; both were released in 1960. When the American television show, Disneyland, traveled to Italy in 1962, he appeared alongside Annette Funicello in two episodes of the mini-movie, Escapade in Florence, singing, playing the guitar, and adding the Italian verses to the jovial tarantella "Dream Boy". Castelnuovo's international breakthrough role arrived with The Umbrellas of Cherbourg, directed by Jacques Demy and an entirely sung-through film, in which he played opposite Catherine Deneuve. Nominated for the American Academy Award for Best Foreign Language Film, the film gained the attention of both film critics and the public, and won the Palme d'Or at the Cannes Film Festival in February of that same year. After some box-office failures Un mondo nuovo, directed by Vittorio De Sica; and his American film debut in the WesternThe Reward, directed by Serge Bourguignon he gained fame as an actor in Italy, thanks to the role of Renzo in the RAI television mini-seriesI promessi sposi. He also starred alongside an international cast of Peter Graves, James Daly, and Bud Spencer in The Five Man Army, directed by Don Taylor, as a Mexican revolutionary; and as Armand in Camille 2000, directed by Radley Metzger. Since then, Castelnuovo has been featured primarily on television serials around Europe, where he has portrayed numerous parts. He appeared as the athletically-sound spokesman for the corn-oil company Cuore from 1977 to 1982. Castelnuovo also appeared briefly as D'Agostino in the Academy Award-winning best-picture filmThe English Patient. He has continued to be active on the Italian theatre stage as well. In 2002, he starred in a production of the 1931 comedy play The Front Page, written by Ben Hecht and Charles MacArthur. He appeared as Kenny Butler in the 2016 The Legacy Run, the prequel movie of the first ever sport-investigative series Sport Crime with sport personalities Daniela Scalia, Luca Tramontin and other sport stars like NHL Marco Baron, Olympic hockeyFlavien Conne, waterpolo Ivan Asic and boxing world champion Stefania Bianchini.
