Žrnovnica is a river in Croatia that springs at the foot of the Mosor, near Dvori village, in Split municipality, and in its short course flows through Žrnovnica and Podstrana settlements, in the wider area of city of Split, in the Split-Dalmatia County.

[1] Žrnovnica is a karst river, and in its upper course, is classified mountain river with very clear and cold waters, faster flow with small rapids and waterfalls.

In its upper course, Žrnovnica passes through a nearly inaccessible gorge, making it a preserved part of the river.

A promenade was made along the lower part of the river bank, and the rest of the bank was overgrown with willows and figs with other aquatic and riparian vegetation.

It was introduced from nearby Jadro river, and it is one of a handful of rivers in Adriatic watershed, along with Jadro, to host this species, others being Vrljika, Neretva, Zeta and Morača.