O. S. Thiagarajan (born April 3, 1947[1]) is a Carnatic Musician based in Chennai. He is the son and disciple of Sangeetha Booshanam O.V.Subrahmanyam. He learnt music from Sangeetha KalanidhiT.M. Thygarajan, while PadmabhushanLalgudi Jayaraman provided guidance/mentorship early in his career. An ‘A- Top’ graded artist of the All India Radio and of Doordarshan, he has been giving a large number of concerts well appreciated and relished. He is regularly featured by all leading sabhas in Chennai as well as throughout India and has been accompanied by top accompanists such as Lalgudi Shri.G.Jayaraman, M.S. Gopalakrishnan , V.V. Subrahmanyam on violin, Palghat Mani Iyer,Dr T.K.Murthy, Palghat Raghu, Karaikudi Mani, Trichy Sankaran, Umayalpuram Sivaraman on mridanagm, Shri.G Harishankar on Kanjira and Vikku Vinayakaram on Ghatam.[2] He has toured many countries, including USA, Canada, Australia, Singapore, Middle East, Malaysia, Hong Kong, South Africa, and many cities in Europe. He worked as Dean, Faculty of Fine Arts, and Annamalai University for 5 years. He has trained many disciples who are active on the concert circuit. S. Mahati, and Dr. S. Ganesh have undergone advanced training under his guidance.