The Sluch or Southern Sluch is a river in Ukraine. It is a right tributary of the Horyn. It has a length of 451 kilometres (280 mi) and a drainage basin of 13,800 square kilometres (5,300 sq mi). The Sluch takes its source in the Ukrainian oblast of Khmelnytskyi. It then flows through the Zhytomyr and Rivne oblasts, and briefly along the Ukrainian-Belarusian border before finally emptying into the Horyn.