Ultras-Zrinjski, official: Klub navijača Ultras-Zrinjski Mostar (Fan club Ultras-Zrinjski Mostar) is the organisation of football supporters of the football club HSK Zrinjski Mostar. They support all sports teams under HŠK Zrinjski (Croatian Sports Club Zrinjski).
The fan club's name was given in 1993. This is the same year that Zrinjski was being brought back to serve Croatian sports interests (ethnic tensions split Mostar's sports community during these years, causing the Croats to resurrect the Zrinjski sports club). The Ultras take their name from the Ultras fan movement in European football.
The official song of the Ultras is Gori brate ('It's burning, brother').