A muscle car is a type of car that is known for its powerful engine and high-performance driving capabilities. The term "muscle car" was first used in 1966 to describe a group of American-made two-door sports coupes with powerful engines designed for high-performance driving. However, the definition of a muscle car is subjective and endlessly debated. Some key characteristics of muscle cars include:

• A large V8 engine in the most powerful configuration offered for a particular model
• Rear-wheel drive
• Being manufactured in the United States in the 1960s or early 1970s (the specific year range of 1964–1973 is sometimes used)

While muscle cars are often two-door, rear-wheel-drive, small to midsize cars with large, powerful eight-valve (V8) engines, high-power pony cars such as the Ford Mustang, Chevrolet Camaro, and the Plymouth Barracuda, and their luxury companions Mercury Cougar, Pontiac Firebird, and the Dodge Challenger in that large, influential, and lucrative 1960s-70s niche, could also qualify as "muscle cars" if outfitted with suitable high-performance equipment. Personal luxury cars are often too expensive to be considered by some to be muscle cars, and sports cars are not considered muscle cars by some definitions. The earliest muscle cars were not particularly fuel-efficient or environmentally friendly, and many muscle car enthusiasts believe the 1949 Oldsmobile Rocket 88 was the first true muscle car. However, the strictest definition of a muscle car is an intermediate-sized, high-performance oriented model, powered by a large V8 engine, at an affordable price.