The state was renamed Tamil Nadu in August 1968 and the strength of its Legislative Assembly became 234.

The Indian National Congress (INC) was the prominent party in the early years of independence. Justice Party headed by Periyar E V Ramasamy was one of the earliest regional parties in the state. Dravida Munnetra Kazhagam (DMK), founded in 1949 by C N Annadurai , himself a former Justice Party member, came to power for the first time in 1967. The other main political party of the state, the AIADMK, was founded in 1972 by Dr M G Ramachandran, on leaving the DMK. The All India Anna Dravida Munnetra Kazhagam (AIDMK) led by M G Ramachandran formed the first state government in 1977. M G R remained in power as the CM for ten years till his death in 1987. DMK, currently headed by M Karunanidhi came to power in 1989. Since then each party has formed the government alternately. Currently Jayaram Jayalalitha of the AIADMK is the Chief Minister. M Karrunanidhi of the DMK has been the Chief Minister of the state five times.

In General Election to the Lok Sabha in 2009 DMK in alliance with INC and VKC won 27 out of 39 seats. DMK is part of the United Progressive Alliance with INC. AIADMK contested the 2009 elections as part of a Third Front with CPI and CPI (M).

The last state assembly elections were held in 2011. The number of elector who Tamil Nadu General Elections Result 2014 voted was 36756813. The number was 78 % of the total number of electors. The AIADMK won 150 seats. Its alliance partners DDMK won 29 seats and the CPI won 10 seats. The DMK, the incumbent government, won 23. The INC won 5 seats. The AIADMK formed the government and the current Chief Minister is Jayaram Jayalalitha of the AIADMK. The Speaker of the Tamil Nadu Legislative assembly is Shri D Jayakumar and the Deputy speaker is Shri P Dhanapal. The Leader of the House is O Panneerselvam and the Leader of the Opposition is Shri Vijaykant.

Tamil Nadu has a unicameral legislature with one house of the State Legislative Assembly. The Tamil Nadu State Legislative Assembly is also known as the Vidhan Sabha. The strength of the state assembly is 234 directly elected members and one member nominated from the Anglo Indian community. The tenure of the house is five year unless it is dissolved.The state has 39 directly elected members in the Lok Sabha and 18 indirectly elected members in the Rajya Sabha in the Indian Parliament.

Regular elections are held for the state assembly and Lok Sabha seats. Apart from these, the state conducts elections for the local bodies including 10 urban municipal corporations, municipalities and town Panchayats.