Shinnyo En is a form of Buddhism established in Japan. It is a sub-school of Vajrayana, which is the esoteric branch of Mahayana Buddhism. There are three major forms of esoteric Buddhism in Japan, including Shingon, Tendai, and Shinnyo En. Shinnyo En is unique in that it has sesshin meditation training, powers of bakku daiju, and is the form of esoteric practice that is open to lay practitioners. Shingon and Tendai teachings are ultimately only available for practice by monks, whereas Shinnyo En practice is open to all.

The Founder, Shinjo Ito, was originally an aircraft engineer in pre-war Japan. In 1936, he resigned and together with his wife founded Shinnyo En. They have since dedicated their lives to religious pursuit.

Shinnyo En has temples and meeting places in many countries. In the United States, temples are located in San Francisco, Los Angeles, Seattle, Honolulu, Chicago, and New York. The temple in Chicago is the largest Buddhist temple in the United States.

Shinnyo En is translated to mean "garden of truth," or "garden of Tathata." Tathata is a fundamental concept in Mahayana philosophy and is interpreted as the true nature of all phenomena or as the original state of things.

Shinnyo En is based on the Nirvana Sutra (Mahaparinirvana Sutra is the long name) which is the final Buddhist sutra. Other Buddhist sutras also have a place in Shinnyo En, but the Nirvana sutra is the most prominent.