Thirumanilaiyur Sitapati Ramana Subramanian (11 December 1938 – 26 February 2018) was an Indian bureaucrat who served as the cabinet secretary of India from August 1996 to March 1998.

On 31 October 2013, the Supreme Court's decision in T. S. R. Subramanian v. Union of India drastically reduced political pressure on top bureaucrats by ruling that they must get an assured minimum tenure in posting.

"Fixed tenure of bureaucrats will promote professionalism, efficiency and good governance," bench observed.

The SC also directed the Centre and state governments to pass an order within three months on giving fixed tenure to civil servants.

The PIL filed by 83 retired bureaucrats including former cabinet secretary T S R Subramanian seeking its directions for insulating bureaucracy from political interference.