Gymnaste Club 'Azur was founded in the residential area in Les Baumettes on 9 July 1904 under the name Gymnaste Club. The club was established in 1904 by Marquis de Massingy d'Auzac, who was head of Federation Sportive des Alpes-Maritimes (Alpes-Maritimes Sporting Federation). Similar to its name, the club's primary focus was the athletics and gymnastics. The 6th July of 1908 was in order to stay associated with the FSAM as well as become a member of the amateur association USFSA that was the leader of French soccer at that time Gymnaste Club de Nice was split into two sections, the new section called Gymnastes Amateurs Club de Nice. The new section was the birthplace of an football club, and after two years the two clubs joined. On September 20, 1919, Nice merged with local club Gallia Football Athletic Club. The club later adopted the club's black and red combination. In 1920 the club was participating within the Ligue du Sud-Est, a regional league that was under the supervision by the French Football Federation. In the league Nice established rivalries to Cannes in addition to Marseille. On 22nd December 1924 it changed the name of its club to Olympique Gymnaste Club de Nice.
In the month of July, 1930 in 1930, in July 1930, the National Council of the French Football Federation approved a vote of 128-20 to support professionalism in French football. Nice as well as the majority of clubs located in southern France are among the very first teams to sign the new rules and became professional and were the first members of the league. In the inaugural season of the league, Nice finished seventh in its group. The following year, Nice finished 13th and was relegated to the league. The club didn't play league football during the following season. They was back to French soccer in the year 1936 in Division 2. Nice was able to spend the following three years within the 2nd division. In 1939 professional football in France was eliminated because of World War II. However, Nice continued to play league football as an amateur club and Nice was part of the Ligue du Sud-Est in 1939 and then the Ligue du Sud in the subsequent seasons.
Following World War II, Nice was reinstated to professional status, and were returned to the 2nd division. The club was promoted into the top division during the 1948-49 season under management of Austrian director Anton Marek. After two years of being among the top ten spots, Nice was now ruled by director Jean Lardi, achieved its first-ever honor by winning the league title during the season 1950/51. The team was led by French internationals Marcel Domingo, Antoine Bonifaci, Abdelaziz Ben Tifour, and Jean Courteaux, as well as the Argentine duo of Pancho Gonzales and Luis Carniglia and the Swede Par Bengtsson. Nice was crowned league champions even though it was in the same position on points with Lille. Nice was named champions because it had greater winnings (18) over Lille (17). The subsequent season, under the newly appointed manager Numa Andoire Nice was crowned champions after winning the league as well as the Coupe de France. For the league competition, Nice was able to defend its title by holding off Bordeaux as well as Lille. The Coupe de France final, Nice was up against Bordeaux and lost to the Aquitaine club 5-3 , thanks to goals scored by several players.
Nice continued to enjoy a successful run throughout the decade, taking home the Coupe de France for the second time in 1954. The club, currently managed by a new and unproven Just Fontaine, faced southern rivals Marseille and won an 1-0 win which saw Victor Nuremberg and Carniglia scoring the goals. Carniglia quit football at the end of the season, and took over as manager of Nice. In his first year in the club, Nice won the league for the third time in a row after being pursued all season long from rivals Marseille and Monaco and Lens as well as Saint-Etienne. Following the season, Fontaine departed the club to join Stade de Reims. Three years following, Nice won the last title of the decade in the year 1959. The club ended its period (1950-1959) by winning four titles in the league as well as two Coupe de France trophies. Nice also participated at the level of European contest for the first time during the 1956-57 season. They lost against Real Madrid in the quarter-finals.
In the years following, Nice struggled to equal the glory in the 1950s, with Reims and later Saint-Etienne, which was able to surpass the club in the 1960s and 1970s. At this point, Nice regularly competed in Division 1 with the only two seasons of Division 2 in 1965 and 1970. Between 1973 and 1976 Nice was able to secure a 2nd-place finishing at the top of the table, which was its most successful finish since winning competition in 1958. After the second finishing, the club finished in lower positions over the subsequent six seasons and were then relegated for the 1981-82 season following finishing 19th. Nice was within the 2nd division prior to being promoted to the highest division in 1985. After six years of finishing in mid-table positions, Nice returned to Division 2.
The year 1997 saw Nice which is now in first division surprised many by winning it the Coupe de France. But, the win was not shocking to most French football fans due to the fact that the club played prior to the final match, where Nice played only Division 2 teams, with the exception for the first division club Bastia. In the final match, Nice won against Guingamp 5-4 in penalties to win the cup. In a more negative point, Nice were relegated from the first division just weeks after they won the Coupe de France in dead the last league. The club played 5 seasons playing within Ligue 2 and returned to Ligue 1 for the 2001-02 season. In the run-up to the start of the season, Nice was unable to fulfill the financial criteria that were set in the DNCG and was then moved into the Championnat National, the third grade that plays French football. But, once it had stabilized through the sale of several members, Nice was allowed in Ligue 1 after successfully appealing. In the 2005-06 season Nice reached Finale of Coupe de la Ligue in 2006 but lost to Nancy by a score of 2-1.
In 2016 the year 2016, a Chinese along with an American consortium headed by Chien Lee and Alex Zheng purchased 80% of the club. For the year 2016-17 Ligue 1 season, Nice placed at third place in its final league standings, and was able to qualify for the final round of the UEFA Champions League.
On the 11th of June, 2018, Patrick Vieira was announced as Nice manager to replace Lucien Favre. The 2018-19 campaign saw Nice was ranked 7th spot on the table.
In July it was revealed the news that Jim Ratcliffe acquired the French club for EUR100 million.
Following a slump in results led to Nice being ranked 11th at the top of Ligue 1 and eliminated from the Europa League, manager Patrick Vieira was dismissed. Vieira's assistant Adrian Ursea, took over as interim manager. Nice would end its 2020-21 Ligue 1 season in ninth position in the list.
On June 28, 2021 Christophe Galtier was appointed as head coach. On June 27, 2022 Lucien Favre returned to Nice as manager.
