The Bröl (also called the Brölbach or the Homburgische Bröl) is a 45.1 km long right tributary of the Sieg in North Rhine-Westphalia, Germany.

The river flows through the districts of Rhein-Sieg-Kreis and Oberbergischer Kreis. The river's source is in the town of Waldbröl at an elevation of 368 meters above sea level. It flows in a southwest direction through the Bergisches Land and past the Homburg Castle. In the town of Ruppichteroth, a small tributary called the Waldbrölbach joins the Bröl. It eventually flows to the town of Hennef where it joins the Sieg at an elevation of 67 meters.