American TESOL Institute or as popularly known as ATI is one of the most reputed teacher training organizations in the world. Starting off in 2002 as primarily an English Language teacher training institute in Tampa, Florida, USA, it has today emerged as a training organization covering all levels of training including school, corporate and Management programs across the globe. ATI has trained thousands of trainers and teachers both online and in class.

ATI's Asia chapter started in 2007 from Bangkok, Thailand. In Thailand alone ATI is present in Bangkok, Chiang Mai and Phuket.  It has also moved on to India, China, Korea and Vietnam. ATI ranks high on the list of teacher training institutes in Asia today.

The ATI India chapter started simultaneously with Thailand . The centers in India are at present in Kolkata in the east and Kerala in the south and Ahmadabad in the north with plans of taking it to other cities very soon. The courses offered by ATI cover elementary school teaching through the Pre and Primary Teachers Training, English language teaching through the TEFL or TESOL program and the non school trainers category through the Train the Trainer program.