Tathagata entered active politics in the mid 70s as a teenager opposing the Emergency clamped by the Indian National Congress (INC).
He joined active politics in the late 1980s when Sri Biju Patnaik took him into the Janata Party and he got elected to the Odisha Legislative Assembly and became an MLA in 1990.
He went on to become a Four term Member of Parliament till 2019 by winning the Dhenkanal-Angul Lok Sabha seat in 1998, 2004, 2009 and 2014 general elections.
In March 2015, Tathagata Satpathy became the first Indian Member of Parliament to hold an official "Ask Me Anything" session on the content-sharing website Reddit.
[3] In April, Satpathy came forward in support of net neutrality, after the Telecom Regulatory Authority of India (TRAI) come out with a consultation paper on over-the-top (OTT) messaging services.
[8][9] Tathagata Satpathy has criticised the ban on cannabis in India, while pointing out the long history of its usage as a ritual and recreational intoxicant.
He has suggested an amendment to the Narcotic Drugs and Psychotropic Substances Act, 1985 to allow recreational and medicinal usage of marijuana.
[15] He had supported a bill introduced by INC MP Shashi Tharoor to decriminalise homosexuality during the 2015 winter session of the Parliament.
[15] Tathagata Satpathy has raised concerns that the Aadhaar project could be used for mass surveillance or ethnic cleansing in the future.
[21] In December 2015, he criticised the Arbitration and Conciliation (Amendment) Bill, 2015 during a debate, saying that the government was favouring big corporations with such laws.