Formation of Districts in Tamilnadu:
Madras State was formed from the Madras Presidency of British province after Indian Independence. After August 1947 Madras State was formed. The Madras state was renamed as Tamil Nadu on 14 January 1969 by Chief Minister C.N.Annadurai. After state reorganizations in 1953 and 1956, Madras State was divided into 13 districts: Chingleput, Coimbatore, Kanyakumari, Madras, Madura, Nilgiris, North Arcot, Ramnad, Salem, South Arcot, Tanjore, Tirunelveli, and Tiruchirappalli.
The newly established Mayiladuthurai district was officially opened on December 28 by Tamil Nadu Chief Minister K Palanisamy. From Nagapattinam district, Mayiladuthurai was made the 38th district of the state. Mayiladuthurai, Sirkazhi, Tarangambadi, and Kuthalam are the four taluks that make up the new district. Check the complete evolution/ Formation of Districts in Tamilnadu below:
Tamil Nadu District name list pdf in Tamil available, Check the link – Tamil Nadu District List PDF
List of Districts in Tamil Nadu and its formation:
Tamilnadu Districts list, headquarters, Early called name and its established date are given below:
| S.No | District | Established on | Early From | Head Office |
| 1. | Chennai | 1 Nov. 1956 (Initially British by 1649) | Madras | Chennai |
| 2. | Madurai | 1 Nov. 1956 (Initially British by 1781) | One of the 13 District of Madras Presidency | Madurai |
| 3. | Tirunelveli | 1 Nov. 1956 (Initially British by 1790) | One of the 13 District of Madras Presidency | Tirunelveli |
| 4. | Thanjavur | 1 Nov. 1956 (Initially British by 1799) | One of the 13 District of Madras Presidency | Thanjavur |
| 5. | Vellore | 30 Sep. 1989 (Initially British by 1801) | North Arcot – Madras Presidency | Vellore |
| 6. | Cuddalore | 30 Sep. 1993(Initially British by 1801) | North Arcot – Madras Presidency | Cuddalore |
| 7. | Coimbatore | 1 Nov. 1956 (Initially British by 1804) | One of the 13 District of Madras Presidency | Coimbatore |
| 8. | Salem | 1 Nov. 1956 (Initially British by 1860) | One of the 13 District of Madras Presidency | Salem |
| 9. | Nilgiris | 1 Nov. 1956 (Initially British by 1882) | One of the 13 District of Madras Presidency | Ooty |
| 10. | Ramanathapuram | 1 Nov. 1956 (Initially British by 1910) | One of the 13 District of Madras Presidency | Ramanathapuram |
| 11. | Tiruchirappalli | 1 Nov. 1956 (Initially British by 1947) | One of the 13 District of Madras Presidency | Tiruchirappalli |
| 12. | Kanniyakumari | 1 Nov. 1956 | One of the 13 District of Madras Presidency | Nagercoil |
| 13. | Dharmapuri | 2 Oct. 1965 | From Salem District | Dharmapuri |
| 14. | Pudukkottai | 14 Jan. 1974 | From Ramanathapuram, Thanjavur and Tiruchirappalli District | Pudukkottai |
| 15. | Erode | 31 Aug. 1979 | From Coimbatore District | Erode |
| 16. | Sivaganga | 15 Mar. 1985 | From Madurai and Ramanathapuram District | Sivaganga |
| 17. | Dindigul | 15 Sep. 1985 | From Madurai District | Dindigul |
| 18. | Thoothukudi | 20 Oct. 1986 | From Tirunelveli District | Thoothukudi |
| 19. | Tiruvannamalai | 30 Sep. 1989 | North Arcot – Madras Presidency | Tiruvannamalai |
| 20. | Nagapattinam | 18 Oct. 1991 | From Thanjavur District | Nagapattinam |
| 21. | Tiruvarur | 18 Oct. 1991 | From Thanjavur District | Tiruvarur |
| 22. | Viluppuram | 30 Sep. 1993 | South Arcot – Madras Presidency | Viluppuram |
| 23. | Virudhunagar | 15 Mar. 1985 | From Madurai and Ramanathapuram District | Virudhunagar |
| 24. | Perambalur | 30 Sep. 1995 | From Tiruchirappalli District | Perambalur |
| 25. | Karur | 30 Sep. 1995 | From Tiruchirappalli District | Karur |
| 26. | Theni | 25 July 1996 | From Madurai District | Theni |
| 27. | Namakkal | 1 Jan. 1997 | From Salem District | Namakkal |
| 28. | Tiruvallur | 1 July 1997 | From Chingleput District | Tiruvallur |
| 29. | Kanchipuram | 1 July 1997 | From Chengalpattu District – Madras | Kanchipuram |
| 30. | Krishnagiri | 9 Feb. 2004 | From Dharmapuri District | Krishnagiri |
| 31. | Ariyalur | 23 Nov. 2007 | From Perambalur District | Ariyalur |
| 32. | Tiruppur | 22 Feb. 2009 | From Coimbatore and Erode District | Tiruppur |
| 33. | Kallakurichi | 8 Jan. 2019 | From Viluppuram District | Kallakurichi |
| 34. | Tenkasi | 18 July 2019 | From Tirunelveli District | Tenkasi |
| 35. | Chengalpattu | 18 July 2019 | From Kanchipuram District | Chengalpattu |
| 36. | Ranipet | 15 Aug. 2019 | From Vellore district | Ranipet |
| 37. | Tirupathur | 15 Aug. 2019 | From Vellore district | Tirupathur |
| 38. | Mayiladuthurai | 28 Dec. 2020 | From Nagapattinam district | Mayiladuthurai |