The Kottenforst is a large forest, about 40 km2 in area, to the south, west and north of the city of Bonn in Germany. It is part of the Rhineland Nature Park (1,045 km2) and forms its eastern side.
The Kottenforst is the southern part of a highland region that lies about 150 to, and known as the Ville, which drops steeply towards the east into the Rhine Valley, but whose western slopes descend more gradually towards the Swist and Erft rivers, forming a geological half-horst. The part of the natural region of Ville, which is not dominated by the brown coal mining of the Rhenish Brown Coal Field, is also called Waldville.
The Kottenforst is divided into a southeastern section between Meckenheim, Bad Godesberg and Bonn, into which areas of natural open country intrude in places, such as the Katzenlochbach Valley, and a northern area between Heimerzheim, Buschhoven and Alfter. Between the two areas lies the village of Witterschlick.
The Kottenforst once was the location of Schloss Herzogsfreude, the hunting lodge of Clemens August of Bavaria, Prince-Elector and Archbishop of Cologne, who loved to go hunting here and also erected the many avenues in the forest.