İstanbul Başakşehir Futbol Kulübü (Turkish pronunciation: [istɑnbuɫ bɑʃɑkʃehiɾ futboɫ kulyby]) is a Turkish professional football club based in the Başakşehir district of Istanbul, Turkey. The club is better known as İstanbul Başakşehir or, due to sponsorship, Medipol Başakşehir (Turkish pronunciation: [medipoɫ bɑʃɑkʃehiɾ]). The club was founded in 1990 as İstanbul Büyükşehir Belediyespor. They first reached the highest level in Turkish Football in 2007–08. They play their home games at the Fatih Terim Stadium in Istanbul and are owned by the Ministry of Youth and Sports.
The club is one of five Süper Lig teams based in Istanbul, along with Fenerbahçe, Galatasaray, Beşiktaş and Kasımpaşa. In the 2016–17 season, they participated in the Süper Lig, Turkish Cup and UEFA Europa League. In the 2017–18 season they reached the play-off round of the UEFA Champions League qualifying round. The head coach since 2014 is Abdullah Avcı.