The NASCAR Whelen Modified Tour (NWMT) is a modified stock car racing series owned and operated by NASCAR in the Modified Division. The Modified Division is NASCAR's oldest division, and is the only open-wheeled division that NASCAR sanctions. NASCAR Whelen Modified Tour events are mainly held in the northeastern United States, but the 2007 and 2008 tours expanded to the Midwest with the addition of a race in Mansfield, Ohio. The tour races primarily on short oval paved tracks, but the NWMT also has made appearances at larger ovals and road courses.

Modified stock car racing, also known as modified racing and modified, is a type of auto racing that involves purpose-built cars simultaneously racing against each other on oval tracks. First established in the United States after World War II, this type of racing was early-on characterized by its participants' modification of passenger cars in pursuit of higher speeds, hence the name.