Yoga Alliance is a U.S.-based non-profit membership trade and professional organization for yoga teachers. The organization is headquartered in Arlington, Virginia. Registered Yoga Teacher (RYT), a title in the United States that designates a yoga teacher who has received a certain standard of yoga teacher training at a Registered Yoga School (RYS), is offered by the Yoga Alliance at the 200-, 300- and 500-hour levels. As of 2007 there were 9,940 yoga teachers who had met the criteria needed to be registered with Yoga Alliance.
The Yoga Alliance says that Yoga Alliance Registry is a voluntary, internationally recognized credentialing system. The teacher Registry is not a certification program, but a listing of teachers who meet Yoga Alliance's Requirements for teaching experience and have completed their trainings at a Registered Yoga School (RYS; Registered Yoga School is a registered trade mark).