Betta keeping began in Thailand (formerly Siam) over 150 years ago. Children collected these territorial fish in rice paddies and would place them together to watch them spar, hence the name Siamese Fighting Fish. Soon, betting on these contests became commonplace. The King of Siam recognized their popularity and decided to regulate and tax them. In 1840, the King gave some fish to a man who, in turn, gave them to Danish physician, Dr. Theodore Cantor. The doctor bred and studied them, later writing a scientific paper that identified them as Macropodus pugnax. When it was discovered that there already was a fish by that name, Charles Tate Regan renamed them Betta splendens, meaning "beautiful warrior", a name that stands to this day. Bettas were first imported into France and Germany in the 1890s, and Mr. Frank Locke of San Francisco, CA, brought the first bettas into the United States in 1910.

Americans sometimes mis-pronounce the name as "bay-tuh" after the second letter in the Greek alphabet, however, it is believed that these fish were actually named after the ancient Asian Bettah warrior tribe – pronounced "bet-tah". (Think "My fish is bettah than yours"!) In Thailand, they are called "plakat", which means "biting fish".