Građanski nogometni klub Dinamo Zagreb, commonly referred to as GNK Dinamo Zagreb or simply Dinamo Zagreb, is a professional Croatian football club based in Zagreb. They are the most successful club in Croatian football, having won 20 Croatian Football League titles, 15 Croatian Football Cups and six Croatian Football Super Cups. The club has spent its entire existence in top flight, having been members of the Yugoslav First League from 1946 to 1991, and then the Croatian First League since its foundation in 1992.
After the Second World War, the new communist regime considered clubs like HŠK Građanski as fascist and nationalistic. As such, they were banned, and, in 1945, NK Dinamo was founded as a club to act as an unofficial successor to HŠK Građanski, getting around the ruling party's disapproval. They entered the Yugoslav First League in its inaugural 1946–47 season, finishing as runners-up. In their second season in Yugoslav top flight in 1947–48 they finished as Yugoslav champions, which was their first major trophy. The club won three more league titles and seven Yugoslav Cups.