Kyu (級) is a Japanese term used in martial arts, chado, ikebana, go and in other similar activities to designate various degrees or levels of proficiency or experience.

In Japanese martial arts kyu usually hold the ranks below black belt. Depending on the school, either all the kyu wear white belts or they wear different coloured belts according to their kyu grade. Using only white belts for kyu is more traditional, but many schools have found the identification of each grade useful to help training progress; a higher belt is something to aim for, whilst identifying a higher grade makes it easier to group beginners with beginners or with someone more experienced as the exercise merits.

In aikido, for example, there are six kyu grades: Rokukyu (6th kyu) white belt, gokyu (5th kyu) yellow belt, yonkyu (4th kyu) orange belt, sankyu (3rd kyu) green belt, nikyu (2nd kyu) blue belt and ikkyu (brown belt) 1st kyu. The colours are said to be symbolic of the level of knowledge; virgin white for the pure, untrained power of the beginner contrasts with the black of the dan grades. Yellow represents a seed, orange is the sunlight it begins to absorb, green represents shoots as the plant grows, blue is the sky the plant moves towards and brown is representative of the trunk of the plant hardening.

The kyu ranking system varies from art to art and may include red and purple belts, tags and stripes.

See also: Go ranks and ratings.