The history of Muay Thai can also be traced to the 16th century. During the battles between the Burmese and Siam, the famous fighter Nai Khanomtom was captured in 1767. The Burmese knew he was an expert in hand-to-hand combat and gave him an opportunity to fight for his freedom. Soon after winning the match, he was freed and allowed to return to Siam. He was acknowledged as a hero and his fighting style became known as Siamese-Style boxing which was later to be known as Muay Thai. This fighting style was soon recognized as a national sport.

As well as being a practical fighting technique for use in actual warfare, muay became a sport in which the opponents fought in front of spectators who went to watch for entertainment.

Muay Thai is referred to as the "Art of Eight Limbs" or the "Science of Eight Limbs", because it makes use of punches, kicks, elbows and knee strikes, thus using eight "points of contact", as opposed to "two points" (fists) in boxing and "four points" (hands and feet) used in other more regulated combat sports, such as kickboxing and savate.

A practitioner of muay Thai is known as a nak muay. Western practitioners are sometimes called Nak Muay Farang, meaning "foreign boxer."