İstanbul Büyükşehir Belediyespor, also known simply as İstanbul BŞB or Istanbul BB, is a professional basketball club[1] based in Istanbul, that plays in the Turkish Basketball Second League, the third tier of Turkey's basketball pyramid.

The club is a part of İstanbul Büyükşehir Belediyesi Spor Kulübü.

The team began playing in the lower divisions of Turkish basketball league systems for 2000 season with amateur players.

Then, the team beat Aydem Pamukkale Üniversitesi in semi-finals and promoted to TBL (now called BSL).

Note: Flags indicate national team eligibility at FIBA-sanctioned events.