Thenkachi Ko. Swaminathan (1946-2009) was a popular orator, television personality and author of various Tamil books. He had served as Deputy Director of All India Radio, Chennai. Swaminathan was born in Thenkachi a small village in Perambalur, Tamilnadu. He graduated in agriculture from the Tamilnadu Agricultural University, Coimbatore.

He started his career in a government office as Agricultural Extension Officer. He resigned his job to do farming in his agricultural lands. Seven years later in 1977 he joined All India Radio, to make speeches on agricultural topics.

He started his oration in Pannai Illam (Farm House) which was an instant hit with the farmers. Through this programme, with his scientific knowledge on agriculture he taught farmers modern agricultural techniques, of course using his inimitable easy style to relate to farmers.

Millions of people across Tamil Nadu woke up to his voice every morning for several years. The five-minute programme, presented in simple colloquial Tamil, the common man could relate to and punctuated by anecdotes meant to make you smile and ponder, was broadcast without a break from 1988 until his retirement in 2002. Many still remember him for his popular daily programme "Indru oru Thagaval" (i.e. Message for the day) on All India Radio (AIR).

He was born in the Thenkachi village, Ariyalur District in Tamil Nadu, India. He is survived by his wife and a daughter. Swaminathan died on Wednesday, 16 September 2009 after a heart attack at the age of 63.