Tiruvengimalai Sesha Sundara Rajan (1880–1953) was an Indian doctor, politician and freedom-fighter who served the Minister of Public Health and Religious Endowments in the Madras Presidency from 1937 to 1939.
Rajan was born in Srirangam in Trichinopoly district and studied medicine at Royapuram Medical School, Madras and England. He practised as a doctor in Burma and England and obtained his M.R.C.S. degree in 1911. In 1923, he set up his own clinic.
Rajan entered the Indian independence movement in 1919 and joined the Indian National Congress. He participated in the agitations against the Rowlatt Act and in the Vedaranyam Salt Satyagraha. He served as the President of the Tamil Nadu Congress Committee and as the Member of the Imperial Legislative Council of India from 1934 to 1936. From 1937 to 1939, he served as the Minister of Public Health in the Madras provincial government.