S. Krishnan is an I.A.S. officer of 1989 batch. He is presently Principal Secretary, Planning, Development and Special Initiatives, Government of Tamil Nadu. He is also in full additional charge as Managing Director, New Tirupur Area Development Corporation; CEO, Tamil Nadu Infrastructure Development Board; Officer on Special Duty, 14th Finance Commission and Chairman, Fifth State Finance Commission. In the Government of Tamil Nadu he has earlier been Secretary (Expenditure) (2011-2013), Commissioner of Commercial Taxes (2011), Joint Secretary, Finance (2000), District Collector, Virudhunagar (1997-2000), Managing Director of Tamil Nadu Text Book Corporation and Member-Secretary of Sports Development Authority of Tamil Nadu (1996-1997) and Sub-Collector, Cuddalore (1991-92).
He was Senior Advisor in the Office of the Executive Director for India, International Monetary Fund, Washington DC from 2007-2010 where he had a ring side view of the multilateral response to the Global Financial Crisis of 2008. He was Government of India’s representative in G20 Expert Groups on International Financial Architecture and Global Financial Safety Nets. From 2004-2007 he was Private Secretary to Finance Minister, Government of India. From 2000–2004 he was Deputy Director (Senior), Lal Bahadur Shastri National Academy of Administration, Mussoorie.