Muay Thai is the Thai name for a form of martial art practiced in several southeast Asian countries including Cambodia (where it is Pradal Serey), Myanmar, and Malaysia (where it is known as tomoi). The different types of fighting in mainland South East Asia is analogous to the different types of Kung Fu in China and Silat in the South East Asian islands or Malay World. It is the national sport of Thailand, and is also known as Thai Boxing or Art of the Eight Limbs.

Traditional Muay Thai has a long history in Thailand as a martial art used by the military since ancient times. The military style of Muay Thai is called Lerdrit, while today's "Sport Muay Thai" slightly varies from the original art and uses kicks and punches in a ring and with gloves similar to those used in western boxing. Muay Thai is referred to as "The Science of Eight Limbs", as the hands, shins, elbows, and knees are all used extensively in this art. A master practitioner of Muay Thai thus has the ability to execute strikes using eight "points of contact," as opposed to "two points" (fists) in boxing and "four points" (fists, feet) used in the primarily sport-oriented forms of martial arts. Muay Thai is an especially versatile, brutal, straightforward martial art.

Muay Thai is considered by some to be a derivation of a general indigenous martial art style native to Southeast Asia. Muay Thai was the first of these styles to be popularized outside of Southeast Asia.