The Tamil Nadu Agricultural University (TNAU) came into being on June 1, 1971.However, it had its genesis from establish-ment of an Agricultural School at Saidapet, Chennai, Tamil Nadu, as early as 1868 and it was later relocated at Coimbatore. In 1920 it was affiliated to Madras University. TNAU assumed full responsibilities of Agricultural Education and Research and supported the State Agricultural Department by delivering research products. Till 1946, the Agricultural College and Research Institute, Coimbatore, was the only Institute for Agricultural Education for the whole of South India. In 1958, it was recognized as a Post-graduate Centre leading to Masters and Doctoral degrees. The Agricultural College & Research Institute, Madurai was established in 1965. These two colleges formed the nucleus of the Tamil Nadu Agricultural University while it was established in 1971.

In 1972, separate degree programmes of B.Sc. (Horticulture) and B.E.(Agriculture) were started. In 1979, a separate Faculty of Horticulture was established. In 1980, B.Sc.(Home Science) programme was started at Madurai campus. The third Agricultural College was started at Killikulam in 1984 and the fourth at Kumulur (Trichy) in 1989 and later shifted to Navalur Kuttappattu (Trichy) in 1992 which is named as Anbil Dharmalingam Agricultural College and Research Institute. During 1985, B.Sc.(Forestry) programme was started at Coimbatore. Presently the B.Sc.(Horticulture) degree programme is being offered at Horticultural College and Research Institute, Periyakulam and B.Sc.(Forestry) degree programme at Forest College and Research Institute, Mettupalayam. In line with technological changes the B.E.(Agriculture) hither to offered is offered as B.Tech.(Agricultural Engineering) from the Academic year 2002-2003 at Agricultural Engineering College & Research Institute, Kumulur, Trichy. B.Sc.(Home Science) degree program is being offered at Home Science College & Research Institute, Agricultural College Campus, Madurai. The Pandit Jawaharlal Nehru College of Agriculture & Research Institute, Karaikal, governed by Government of Pondichery, is an affiliated institute of Tamil Nadu Agricultural University where B.Sc.(Agriculture) course is being offered. Apart from these academic institutes, the University now has research programs at more than 32 stations, spread over in Tamil Nadu with more than 1000 scientists and teachers.

The global technological developments has lead to introduction of new courses. Introduction of B.Tech.(Food Process Engineering) from the academic year 1998-99, B.Tech.(Agricultural Biotechnology) and B.Tech.(Horticulture) from the academic year 2002-2003 as self supporting program has created avenues for bugetary independence. A new degree program B.Tech.(Energy and Environmental Engineering) was started during 2004 and B.Tech.(Bioinformatics) during 2006.

The milestones of growth and development of TNAU in transforming lives of Farmers.
1868 Agricultural School was started at Saidapet, Chennai (Madras)
1906 The Saidapet Agricultural School was shifted to Coimbatore and foundation stone laid for Madras Agricultural College.
1908 Students were admitted to education program leading to Licentiate in Agriculture (L. Ag.)
1909 Opening of Agricultural College and Research Institute (AC & RI) by Sir Arthur Lawley.
1920 The AC & RI was affiliated to Madras University. A new course of study leading to a three year degree in Agriculture -B.Sc. (Ag.) was started.
1945 Second Agricultural College was started at Bapatla (Now in Andhra Pradesh).
1958 Regional Post-Graduate Center was established to offer programs leading to Masters degree in Agriculture & Horticulture.
1960 Integrated system with four year B.Sc. (Ag) degree program after Pre-University education was introduced and subsequently doctoral program in Agriculture was started.
1965 Third Agricultural College was started at Madurai, Tamil Nadu and the Masters program at Madurai was introduced during 1969.
1971 The Tamil Nadu Agricultural University came into existence with Coimbatore as its Head Quarters.
1972 A separate Faculty of Horticulture was established and a degree program in Horticulture - B.Sc. (Hort.) was introduced. The College of Agricultural Engineering was established at Coimbatore and a Bachelor's degree program in Agricultural Engineering - B.E.(Ag) was introduced.
1973 Doctoral program was introduced in Horticultural College and Research Institute, Coimbatore.
1975 Faculty of Post Graduate Education was established in TNAU, Coimbatore and Masters and Doctoral (1978) programs were started in Environmental Sciences and Biotechnology.
1976 The Madras Veterinary College became constituent unit of TNAU and B.V.Sc. degree program was suitably restructured*.
1977 Bachelor's degree (B.F.Sc.) program in Fisheries Science at Thoothukudi was started*.
  Masters and Doctoral program in Agricultural Engineering was introduced.
1980 Bachelor's degree (B.Sc. (H.Sc.)) in Home Science was launched in Madurai Campus.
1981 Masters program was introduced in Home Science College & Research Institute, Madurai and Doctoral program in 1988.
1989 Doctoral program in Agriculture was introduced in Agricultural college & Research Institute, Madurai; Masters program introduced in Forest College & Research Institute, Mettupalayam and Horticultural College & Research Institute, Periyakulam.
1990

Masters program in Agriculture was introduced in Agricultural College & Research Institute, Killikulam, Thoothukudi district, Tamil Nadu and Doctoral program in Forest College & Research Institute, Mettupalayam.
1998 B.Tech.(Food Process Engineering) introduced as self supporting program.
2002 B.Tech.(Horticulture) and B.Tech(Agricultue Biotechnology) introduced as self supporting programs.
2004 B.Tech.(Energy and Environmental Engineering) introduced as a self supporting program.
2005 Centenary celebrations of AC&RI, Coimbatore
2006 B.Tech.(Bioinformatics) introduced as a self supporting program.