Renzo Calegari started his professional career in the art studios of Roy d'Ami in 1954. A year later, he drew 'El Kid' and 'I Tre Bill', both written by Gianluigi Bonelli. Again with Bonelli, he produced 'Davy Crockett' (at first named 'Big Davy', because of another series with the same name). From 1957 to 1966 he also drew for the London based Fleetway agency, doing mainly 'Battler Britton' and stories for the Thrilling Picture Library. From 1967 he illustrated numerous episodes of Gino d'Antonio's 'La Storia del West'.
Calegari left the comics field in 1969 to spend all his time on his political activities (the Italian communist party). He returned to comics in 1977, when he drew the western 'Welcome to Springville', in cooperation with Ivo Milazzo and with a script by Giancarlo Berardi. Calegari also created the 'Boone' series in Il Giornalino and cooperated on such series as 'Ken Parker' and 'Tex Willer'.