Topľa (Hungarian: Tapoly, German: Töpl) is a river in eastern Slovakia and right tributary of Ondava. It is 129.8 km long and its basin covers an area of 1,503 km². It rises in the Čergov mountains, flows through Ondava Highlands, Beskidian Piedmont, Eastern Slovak Hills and Eastern Slovak Flat and flows into Ondava in the cadastral area of Parchovany.