The Annamalai University (AU) is a public state university in Chidambaram, Tamil Nadu, India. The 1,500-acre (6.1 km²) sprawling campus offers courses of higher education in arts, science, engineering, management, humanities, agriculture, and physical education. With over 32,480 students residing on campus, it is one of the largest teaching, and residential universities in Asia, and is among the most reputed and ranked universities in India including the rankings from NIRF, QS World University Rankings, Times University Rankings, CWTS Leiden Ranking, India Today Magazine, India Today MDRA, AISHE, ARIIA, SCImago Institutions Rankings.

The National Assessment and Accreditation Council has conferred accreditation to the university in the fourth cycle, and subsequently with its highest A+ grade in 2022. Annamalai University is also recognized among the top 18 universities in India having the 'Centre with Potential for Excellence in Particular Area (CPEPA)' with a focus on drug development and climate change.

Established in 1929, it is one of the oldest and among the most prestigious universities in India. The university was also ranked as 18th most influential institution in India and, It is also among the topmost google searched universities in India as well as in the World.

Annamalai University is a member of the Association of Indian Universities (AIU) and The Association of Commonwealth Universities (ACU). All the degrees awarded by Annamalai University senate are mutually recognized by all Indian Universities and Foreign Universities under the commonwealth fold. The Division of Continuing Education or Directorate of Distance Education of the university is also a permanent member of AMDISA (Association of Management Development Institutions in South Asia) that provides the SAQS Accreditation (South Asian Quality System) to the Institutions.

The university was founded in 1929 by the entrepreneur Rajah Sir S. Rm. M. Annamalai Chettiar in the aftermath of the Montagu–Chelmsford Reforms. In the early 1920s, to serve the downtrodden and to promote Tamil literature, Rajah Sir S. R. M. Annamalai Chettiar founded Sri Minakshi College, Sri Minakshi Tamil College and Sri Minakshi Sanskrit College in a rural setup at Chidambaram. In 1928, Rajah Sir S. R. M. Annamalai Chettiar agreed with the local government to hand over the above said institution for establishing a university. Thus, on 1 January 1929 Annamalai University was established as per Annamalai University Act 1928 (Tamil Nadu Act 1 of 1929). The most significant development is the enactment of the Annamalai University Act, 2013 (Tamil Nadu Act 20 of 2013), which came into force from 25 September 2013, after obtaining the assent of the President of India.

The university has ten faculties, namely agriculture, arts (including management studies), education, engineering and technology, fine arts, Indian languages, marine sciences, and science.

The organizational structure of Annamalai University consists of the Senate, the Syndicate, the Academic Council, the faculties, the Finance Committee, and the Boards of studies. The governor of Tamil Nadu is the chancellor of the university. The vice-chancellor is the executive head of the university. The registrar of the university, who is the secretary of the Syndicate, is the custodian of all the records and chief administrator of the university. The examinations of the university is managed by Office of the Controller of Examinations.

Annamalai University is one of the largest unitary, teaching, and residential Universities in Southern Asia consisting of 10 faculties and 49 departments of study. This university has played a pivotal role in providing access to higher education to thousands of youths cutting across the social spectrum, especially from economically and socially disadvantaged classes. In this respect, this university's service to the Nation is tremendous. Annamalai University is organized into ten main schools, each of which comprises multiple departments and centres as below.^{[citation needed]}