A monster truck is an automobile, typically a pickup truck, which has been modified with extremely large wheels and suspension. They are used for popular entertainment, particularly among rural residents in the United States, where they are featured alongside Motocross races, tractor pulls , and car-eating robot dinosaurs.

Typically, a monster truck show involves the truck crushing smaller vehicles beneath its huge tires. These trucks can run up and over most man-made barriers, so they are equipped with remote shut-off switches to prevent a runaway truck from running over the grandstand and into the audience.

The first, and best-known, monster truck is Bigfoot.

A familiar 1980s series of radio commercials for various monster truck races featured a screaming announcer, blaring rock background music, and heavy use of reverb, and usually began each spot with "Thiiiiiis Sunday!!!" The ads have been frequently parodied in other advertisements.