The Jadro is a watercourse in Dalmatia, Croatia, that discharges into the Adriatic Sea. The upper reaches of the Jadro River, as well as its source, Jadro Spring, are protected as an ichthyological nature reserve, partly due to the presence of an endemic species of soft-mouthed trout. The headwaters of the Jadro River were the original water supply for the ancient city comprised by Diocletian's Palace (now an area within the present day city of Split). Contemporary studies indicate favourable water quality levels of the river near the headwaters at Jadro Spring.
The Jadro flows through the town of Solin and has a length of approximately four kilometres' moreover, the river provides water to the cities of Split, Kaštela and Trogir as well as of municipalities Podstrana, Klis, Seget and Okrug. Incompliances with the regulations related to water for consumption occasionally appear due to turbidity caused by abundant precipitation.
