The Radomka is a river in central Poland and a left-bank tributary of the Vistula.

The river has its source in forests 4 km south of Przysucha, at a height of 310 meters above sea level.

There is a retention reservoir, built in the valley of the Radomka in Domaniów, which has the largest surface area of any lakes in Mazowsze Voivodeship (5 – 7 km2).

After flowing through the hills of the Lesser Poland Upland, the Radomka enters a wide urstromtal, to finally join the Vistula near Ryczywol, at 160 meters above sea level.

It aims to preserve natural wilderness, with its fir and beech trees.