Monsters of Rock is a hard rock and heavy metal music festival. It was originally held annually in Castle Donington, England, from 1980 to 1996, taking place every year except 1989 and 1993. It later branched into other locations such as the Netherlands, Poland, Spain, Italy, Germany, France, Sweden, Argentina, Brazil, Chile, Colombia, the United States, and Russia.

Castle Donington is a market town and civil parish in Leicestershire, England, on the edge of the National Forest and close to East Midlands Airport.