Campobasso made its debut in 1919 and reached the height of its success in the 1980s when the club was promoted to Serie B and played five consecutive seasons in the second tier of Italian football.
Until 1929, the club played its games primarily against military opponents as well as regional teams such as Isernia, Benevento and Chieti.
The club's first promotion took place in the 1933–34 season when it won a spot in the Prima Divisione under the guidance of head coach Armand Halmos.
Competing in the fourth tier in 1952, they played for some years at that level till being admitted to the newly established Serie D league in 1959.
Campobasso's debut in Serie B saw the club finish 13th in the table, comfortably avoiding relegation and also achieving impressive results such as a win against a Fiorentina side that featured 1982 FIFA World Cup champions Giancarlo Antognoni and Francesco Graziani.
The 1984–85 season saw Campobasso experience several changes, among them the departures of captain Michele Scorrano and head coach Antonio Pasinato; the team avoided relegation only on the final matchday of the season against Triestina but also had the chance to debut their brand-new stadium, Stadio Nuovo Romagnoli, which was inaugurated with the most prestigious victory in the history of the club to date: a 1–0 Coppa Italia win against Italian powerhouse Juventus, led by Giovanni Trapattoni, with an attendance of 40,000 fans, far surpassing the 26,000 capacity of the stadium.
For the 1986–87 season, Tord Grip was hired as the new manager but quickly proved to be unsuccessful in his role, being fired after just two wins in their first 12 games.
The following three seasons saw Campobasso finish mid-table in Serie C2 before the club was deemed ineligible to play by the Italian Federation.
The remainder of the 2010s saw Campobasso compete primarily in Serie D, where the club finished consistently safe of the relegation zone.
In December 2020, New York–based North Sixth Group, led by Matt Rizzetta, acquired a minority ownership stake in Campobasso, buying 11 percent of the club with an option to increase its stake to 51 percent in the event of promotion to Serie C. In their first season as co-owners, Gesue and Rizzetta proved to be a successful duo, with the club topping the table for nearly the entire season and eventually achieving promotion to Serie C and a spot in the third tier of Italian football for the first time in 32 years.
For this reason, the club decided to relieve coach Andrea Mosconi and DS Pino de Filippis of their duties on November 11.
They defeated league leader (and previously unbeaten) Sambenedettese on the 14th match day concluding the round in first place.
After a very tightly contested season in Group F, Campobasso conquered the league title thus obtaining a second consecutive promotion returning to the professional ranks.