Oolong is a traditional Chinese type of tea somewhere in between green and black in oxidation.

The term "oolong" means "black dragon" or "black snake" in Chinese; various legends describe the origin of this curious name. In one legend, the owner of a tea plantation was scared away from his drying tea leaves by the appearance of a black snake; when he cautiously returned several days later, the leaves had been oxidized by the sun and gave a delightful brew.

Another tale tells of a man named Wu Liang (later corrupted to Wu Long, or Oolong) who discovered oolong tea by accident when he was distracted by a deer after a hard day's tea-picking, and by the time he remembered about the tea it had already started to oxidise. Others say that the tea is called "oolong" because the leaves look like little black dragons which wake when you pour hot water on them.

"Oolong" tea leaves are distinguished, when dried, by their black thread-like appearance.