NK 칼로박

Traditionally lower-level minnows, the club's most successful period in the Yugoslav football league system was in the 1970s when they competed in the Yugoslav Second League. After the breakup of Yugoslavia and the formation of the Croatian football league system in 1992 Karlovac spent most of the time playing in Druga HNL and Treća HNL, second and third levels.

Led by manager Igor Pamić, Karlovac won consecutive promotions in the 2007–08 and 2008–09 seasons, which saw them join the top level for the first time in their history. After a sixth-place finish in debut season in 1. HNL and equally good second season, financial troubles during 2011–12 season hit Karlovac hard. They faced relegation to second division but due to financial irregularities, Karlovac was suspended by Croatian Football Federation.

In summer of 2012, NK Karlovac 1919 was founded as a successor club but the two clubs' track records and honors are kept separate by the Croatian Football Federation.

Former names

Founded in 1919 as NK Borac, they changed their name in 1920 to NŠK Karlovac. This lasted until 1941 when they merged with several local sides to form ŠK Velebit. Following World War II Velebit was disbanded and re-established as FD Udarnik, which was then renamed in 1948 SD Slavija before adopting their current name NK Karlovac in 1954.^[]

• Borac (1919–1920)
• NŠK Karlovac (1920–1941)
• HŠK Velebit (1941–1945)
• Udarnik (1945–1948)
• Slavija (1948–1954)
• Karlovac (1954–1958)
• KSD (1958–1960)
• Karlovac (1960–2012)