HKK Zrinjski Mostar (Croatian: Hrvatski košarkaški klub Zrinjski Mostar, English: Croat Basketball Club Zrinjski Mostar) is a basketball team from the city of Mostar, Bosnia and Herzegovina. The club plays in the Basketball Championship of Bosnia and Herzegovina.

The club is part of the Zrinjski Mostar sport society. Since the national championship was formed in 1997, it has spent all but two seasons in the top league: the inaugural season and the 2003–04 season. For the 2003–04 season, Zrinjski was relegated to the regional Croatian league, but bounced back the following year to return to the top level of play. Since its return to the national championship it has placed in the top half of the table as well as reaching the semifinals in the national cup twice.

The club's current coach is Zoran Glomazić. A feeder club, often known as Zrinjski II, plays in the lower Croatian league. Fans of HKK Zrinjski are known as Ultras.

In 2018, the club won their first National league title.

Note: Flags indicate national team eligibility at FIBA-sanctioned events. Players may hold other non-FIBA nationalities not displayed.