Kocaelispor

Kocaelispor is a Turkish professional football club based in İzmit, Kocaeli. They were founded in 1966 and played in the top level between 1980 and 1988, 1992–2003, and the 2008–09 seasons. Their best finish was in the 1992–93 season, where they finished fourth. They have won the Turkish Cup twice, in 1997 and 2002. On 8 January 2015, in front of 20,152 spectators, Kocaelispor set a record for the highest attendance at a Turkish Regional Amateur League encounter.

Known as Körfez’in Şimşekleri (Thunderbolts of the Gulf), the club enjoys strong local support in the city of İzmit and the Kocaeli province. Their home matches are played at the modern Kocaeli Stadium, which has a capacity of 34,712. The club’s traditional colours are green and black. Kocaelispor has a well-known rivalry with Sakaryaspor, known as the Körfez Derbisi (Gulf Derby), which is one of the most intense regional derbies in Turkish football.

In recent years, the club experienced a remarkable resurgence after facing major financial and sporting difficulties during the 2010s, which saw them relegated to the amateur divisions. Following a period of restructuring and rebuilding, they achieved multiple promotions in the Turkish league system. In the 2023–24 season, Kocaelispor finished 6th in the TFF First League and qualified for the play-offs, where they were eliminated in the quarter-finals. In the following 2024–25 season, the team secured promotion to the Süper Lig with three matches remaining, marking their return to the top flight after 16 years.