Before 1947 edit

Before 1947, Madras Presidency under British Raj was made up of 26 districts, of which 12 districts were part of the boundaries of the present-day Tamil Nadu, namely, Chingleput, Coimbatore, Nilgiris, North Arcot, Madras, Madura, Ramnad, Salem, South Arcot, Tanjore, Tinnevely, and Trichinopoly.^[1]

1947–56 edit

After Indian Independence, the Madras Presidency] became the Madras Province on 15 August 1947. Pudukottai, a princely state acceded to the Indian Union on 4 March 1948 and became a division in Trichinopoly district.^[2] When the new constitution came into force on 26 January 1950, Madras Province became Madras State. Madras state included most of the present-day Tamil Nadu, Coastal Andhra and Rayalaseema of Andhra Pradesh, the Malabar region of Kerala, Bellary and South Canara districts of Karnataka.^[3] Coastal Andhra and Rayalaseema were separated to form Andhra State in 1953.^[4] As a result of the re-organization of states in 1956, South Canara and Bellary districts were merged with Mysore State to form Karnataka and Malabar district with the State of Travancore-Cochin to form Kerala in 1956.^[5] The Tamil speaking regions of Kanyakumari which was earlier a part of Travancore-Cochin was merged to Madras state.^[5] Madras state had 13 districts namely: Chingleput, Coimbatore, Kanyakumari, Madras, Madurai, Nilgiris, North Arcot, Ramanathapuram, Salem, South Arcot, Thanjavur, Tiruchirappalli and Tirunelveli.^[6]

1957–89 edit

• On 2 October 1965, Dharmapuri district was bifurcated from the erstwhile Salem district comprising Dharmapuri, Harur, Hosur and Krishnagiri taluks.^[7]
• In 1969, Madras State was renamed as Tamil Nadu.^[8]
• On 14 January 1974, Pudukkottai district was formed from the parts of Tiruchirappalli] and Thanjavur districts comprising Kulathur, Thirumayam, Alangudi and Aranthangi taluks.^[2]
• On 31 August 1979, Erode district was bifurcated from the erstwhile Coimbatore district comprising Gobichettipalayam and Erode taluks.^[9]
• On 8 March 1985, Sivaganga and Virudhunagar districts were formed from the erstwhile Ramanathapuram district with Sivaganga comprising Tirupattur, Karaikudi, Devakottai, Sivaganga, Manamadurai and Ilayangudi taluks and Virudhunagar comprising Srivilliputhur, Virudhunagar, Tiruchuli, Aruppukottai, Sattur and Rajapalayam taluks.^[10][11]
• On 15 September 1985, Dindigul district was bifurcated from the erstwhile Madurai district comprising Dindigul, Palani and Kodaikanal taluks.^[12]
• On 20 October 1986, Thoothukudi district was bifurcated from the erstwhile Tirunelveli district comprising Thoothukudi, Ottapidaram and Tiruvaikuntam taluks.^[13]
• On 30 September 1989, Tiruvannamalai and Vellore districts were formed from the erstwhile North Arcot district with Tiruvannamalai district comprising Tiruvannamalai, Arni, Vandavasi, Cheyyar, Polur and Chengam taluks^[14] and Vellore district comprising Arakkonam, Arcot, Gudiyatham, Tirupattur, Vellore, Vaniyambadi and Walajapet taluks.^[15]

1990–99 edit

• On 18 October 1991, Nagapattinam was bifurcated from the erstwhile Thanjavur district comprising Tiruvarur, Mayiladuthurai, Manargudi, Needamangalam, Nagapattinam taluks and Valangaiman from Kumbakonam taluk.^[16]
• On 30 September 1993, Cuddalore and Viluppuram districts were formed from the erstwhile South Arcot district with Cuddalore district comprising Cuddalore, Chidambaram and Vriddachalam taluks and Villupuram district comprising Kallakuruchi, Villupuram, Tirukkoyilur and Tindivanam taluks.^[17][18]
• On 30 September 1995, Karur and Perambalur districts were split from the erstwhile Tiruchirappalli district with Karur district comprising Karur, Kulithalai and Manapparai taluks and Perambalur district comprising Perambalur and Kunnam taluks.^[19][20]
• On 25 July 1996, Theni district was bifurcated from the erstwhile Madurai district comprising Theni, Bodinayakanur, Periyakulam, Uthamapalayam and Andipatti taluks.^[21]
• On 1 January 1997, Tiruvarur district was formed from the parts of erstwhile Nagapattinam and Thanjavur districts comprising Tiruvarur, Nannilam, Kudavasal, Needamangalam, Mannargudi, Thiruthiraipoondi taluks from Nagappatinam district and Valangaiman taluk from Thanjavur district.^[22]
• On 1 January 1997, Namakkal district was bifurcated from the erstwhile Salem district comprising Namakkal, Tiruchengode, Rasipuram and Paramathi-Velur taluks.^[23]
• On 1 July 1997, Kanchipuram and Tiruvallur districts were split from the erstwhile Chengalpattu and Chennai districts with Kanchipuram district comprising Kanchipuram, Sriperumbudur, Uthiramerur, Chengalpattu, Tambaram, Tirukalukundram, Maduranthakam and Cheyyur taluks and Tiruvallur district comprising Tiruvallur, Tiruttani, Ponneri and Gummidipoondi taluks.^[24]

2000–present edit

• On 9 February 2004, Krishnagiri district was bifurcated from the erstwhile Dharmapuri district comprising Krishnagiri, Hosur, Pochampalli, Uthangarai and Denkanikottai taluks.^[25]
• On 19 November 2007, Ariyalur district was bifurcated from the erstwhile Perambalur district comprising Ariyalur, Udayarpalayam and Sendurai taluks.^[26]
• On 24 October 2009, Tiruppur district was formed from the parts of Coimbatore and Erode districts comprising Tiruppur, Udumalpet, Palladam and parts of Avinashi taluks of Coimbatore district and Dharapuram, Kangeyam and parts of Perundurai taluk of Erode district.^[27]
• On 5 January 2018, the Chennai district was expanded by the addition of Madhavaram, Maduravoyal, Ambattur, Tiruvottriyur taluks and parts of Ponneri taluk of Tiruvallur district and Alandur and Sholinganallur taluks of Kanchipuram district.^[28]
• On 22 November 2019, Tenkasi district was bifurcated from the erstwhile Tirunelveli district comprising Tenkasi, Sengottai, Kadayanallur, Sivagiri, Veerakeralampudur, Sankarankovil, Thiruvenkatam and Alangulam taluks.^[29]
• On 26 November 2019, Kallakurichi district was bifurcated from the erstwhile Viluppuram district comprising Kallakurichi, Sankarapuram, Chinnasalem, Ulundurpet, Thirukovilur and Kalvarayanmalai taluks.^[30]
• On 29 November 2019, Tirupattur and Ranipet districts were trifurcated from the erstwhile Vellore district with Tirupattur district comprising Tirupattur, Vaniyambadi, Natrampalli and Ambur taluks and Ranipet district comprising Walajah, Arcot, Nemili and Arakkonam taluks.^[31]
• On 30 November 2019, Chengalpattu district was bifurcated from the erstwhile Kanchipuram district comprising Tirukalukundram], Chengalpattu, Madurantakam, Cheyyar, Tiruporur, Tambaram, Pallavaram and Vandalur taluks.^[32]
• On 24 March 2020, Mayiladuthurai district was bifurcated from the erstwhile Nagapattinam district comprising Mayiladuthurai, Sirkazhi, Tharangambadi and Kuthalam taluks.^[33]

Active districts edit

No.	District	Code	Headquarters	Estd.	Predecessor	Area (km2)[34]	Population[34]	Pop. density (/km2)	Divisions[35]	Taluks[35]	Assembly constituencies	Lok sabha constituencies	Map
1	Ariyalur	ARI	Ariyalur	23 November 2007	Perambalur	2,027.6	754,894	372	Ariyalur Udayarpalayam	Andimadam Ariyalur Sendurai Udayarpalayam	Ariyalur Jayankondam	Chidambaram
2	Chengalpattu	CHG	Chengalpattu	29 November 2019	Kanchipuram	2,802.6	2,556,244	912	Chengalpattu Madurantakam Tambaram	Chengalpattu Cheyyur Madurantakam Pallavaram Tambaram Thiruporur Thirukazhukundram Vandalur	Cheyyur Chengalpattu Maduranthakam Pallavaram Tambaram Thiruporur	Kancheepuram Sriperumbudur
3	Chennai (formerly Madras)	CHN	Chennai	1 November 1956	None	462.3	46,46,732	10,052	Chennai Central Chennai North Chennai South	Alandur Ambattur Aminjikarai Ayanavaram Egmore Guindy Madhavaram Maduravoyal Mambalam Thirumayilai Perambur Purasawalkam Sholinganallur Tiruvottiyur Tondiarpet Velachery	Alandur Ambattur Anna Nagar Chepauk-Thiruvallikeni Dr. Radhakrishnan Nagar Egmore Harbour Kolathur Maduravoyal Madhavaram Perambur Royapuram Saidapet Sholinganallur Thiru-Vi-Ka Nagar Thirumayilai Thiruvottiyur Thousand Lights Thyagaraya Nagar Velachery Villivakkam Virugambakkam	Chennai Central Chennai North Chennai South Sriperumbudur Thiruvallur
4	Coimbatore	COI	Coimbatore	1 November 1956	None	4,950.7	3,458,045	699	Coimbatore North Coimbatore South Pollachi	Anaimalai Annur Coimbatore North Coimbatore South Kinathukadavu Madukkarai Mettupalayam Perur Pollachi Sulur Valparai	Kavundampalayam Kinathukadavu Mettupalayam Pollachi Coimbatore North Coimbatore South Singanallur Sulur Thondamuthur Valparai	Coimbatore Nilgiris Pollachi
5	Cuddalore	CUD	Cuddalore	30 September 1993	South Arcot District	3,870	2,605,914	673	Chidambaram Cuddalore Vriddachalam	Bhuvanagiri Chidambaram Cuddalore Kattumannarkoil Kurinjipadi Panruti Srimushnam Titakudi Veppur Vriddachalam	Bhuvanagiri Chidambaram Cuddalore Kattumannarkoil Kurinjipadi Neyveli Panruti Tittakudi Virudhachalam	Chidambaram Cuddalore
6	Dharmapuri	DHA	Dharmapuri	2 October 1965	Salem	4,735.7	1,506,843	318	Dharmapuri Harur	Dharmapuri Harur Karimangalam Nallampalli Palacode Pappireddipatti Pennagaram	Dharmapuri Harur Palacode Pappireddipatti Pennagaram	Dharmapuri
7	Dindigul	DIN	Dindigul	15 September 1985	Madurai	6,289.1	2,159,775	343	Dindigul Kodaikanal Palani	Athoor Dindigul-East Dindigul-West Gujiliamparai Kodaikanal Natham Nilakottai Oddanchattiram Palani Vedasandur	Athoor Dindigul Natham Nilakottai Oddanchatram Palani Vedasandur	Dindigul Karur
8	Erode	ERO	Erode	31 August 1979	Coimbatore	6,036	2,251,744	373	Erode Gobichettipalayam	Anthiyur Bhavani Erode Gobichettipalayam Kodumudi Modakurichi Nambiyur Perundurai Sathyamangalam Thalavadi	Anthiyur Bhavani Bhavanisagar Erode East Erode West Gobichettipalayam Modakkurichi Perundurai	Erode Nilgiris Tiruppur
9	Kallakurichi	KAL	Kallakurichi	26 November 2019	Viluppuram	3,440.8	1,370,281	398	Kallakkurichi Thirukoilur	Chinnasalem Kallakkurichi Kalvarayan Malai Sankarapuram Thirukoilur Ulundurpet Vanapuram	Kallakkurichi Rishivandiyam Sankarapuram Tirukkoyilur Ulundurpettai	Kallakkurichi Viluppuram
10	Kancheepuram	KAC	Kancheepuram	1 July 1997	Chingleput	1,800.2	1,166,401	648	Kancheepuram Sriperumbudur	Kancheepuram Kundrathur Sriperumbudur Uthiramerur Walajabad	Kancheepuram Sriperumbudur Uthiramerur	Kancheepuram Sriperumbudur
11	Kanyakumari	KAY	Nagercoil	1 November 1956	None	1,729.2	1,870,374	1,082	Nagercoil Padmanabhapuram	Agastheeswaram Kalkulam Killiyoor Vilavancode Thiruvattar Thovalai	Colachal Kanniyakumari Killiyur Nagercoil Padmanabhapuram Vilavancode	Kanniyakumari
12	Karur	KAR	Karur	30 September 1995	Tiruchirappalli	3,022.3	1,064,493	352	Karur Kulithalai	Aravakurichi Kadavur Karur Krishnarayapuram Kulithalai Manmangalam Pugalur	Aravakurichi Karur Krishnarayapuram Kulithalai	Karur Perambalur
13	Krishnagiri	KRI	Krishnagiri	9 February 2004	Dharmapuri	5,414.4	1,883,731	348	Hosur Krishnagiri	Anchetty Bargur Denkanikottai Hosur Krishnagiri Pochampalli Shoolagiri Uthangarai	Bargur Hosur Krishnagiri Thalli Uthangarai Veppanapalli	Krishnagiri
14	Madurai	MAD	Madurai	1 November 1956	None	3,846.4	3,038,252	790	Madurai Melur Usilampatti	Madurai-East Madurai-North Madurai-South Madurai-West Kallikudi Melur Peraiyur Thirumangalam Thirupparankundram Usilampatti Vadipatti	Madurai Central Madurai East Madurai North Madurai South Madurai West Melur Sholavandan Thirumangalam Thiruparankundram Usilampatti	Madurai Theni Virudhunagar
15	Mayiladuthurai	MAY	Mayiladuthurai	28 December 2020	Nagapattinam	1,237.1	918,356	742	Mayiladuthurai Sirkazhi	Kuthalam Mayiladuthurai Sirkazhi Tharangambadi	Mayiladuthurai Poompuhar Sirkazhi	Mayiladuthurai
16	Nagapattinam	NAG	Nagapattinam	18 October 1991	Thanjavur	1,459	697,069	478	Nagapattinam Vedaranyam	Kilvelur Nagapattinam Thirukkuvalai Vedaranyam	Kilvelur Nagapattinam Vedaranyam	Nagapattinam
17	Namakkal	NAM	Namakkal	1 January 1997	Salem	3,573.4	1,726,601	483	Namakkal Thiruchengode	Kollimalai Kumarapalayam Mohanur Namakkal Paramathi-Velur Rasipuram Senthamangalam Thiruchengode	Namakkal Kumarapalayam Paramathi-Velur Rasipuram Senthamangalam Thiruchengode	Erode Namakal
18	Nilgiris	NIL	Ooty	1 November 1956	None	2,452.5	735,394	300	Coonoor Gudalur Udagamandalam	Coonoor Gudalur Kotagiri Kundah Pandalur Udagamandalam	Coonoor Gudalur Udagamandalam	Nilgiris
19	Perambalur	PER	Perambalur	30 September 1995	Tiruchirappalli	1,836.6	565,223	308	Perambalur	Alathur Kunnam Perambalur Veppanthattai	Kunnam Perambalur	Chidambaram Perambalur
20	Pudukkottai	PUD	Pudukkottai	14 January 1974	Thanjavur and Tiruchirappalli	4,847.8	1,618,345	334	Aranthangi Illuppur Pudukkottai	Alangudi Aranthangi Avadaiyarkoil Gandarvakottai Illuppur Karambakkudi Kulathur Manamelkudi Ponnamaravathi Pudukkottai Thirumayam Viralimalai	Alangudi Aranthangi Gandarvakottai Pudukottai Thirumayam Viralimalai	Karur Ramanathapuram Sivaganga Tiruchirappalli
21	Ramanathapuram	RAM	Ramanathapuram	1 November 1956	None	4,243.1	1,353,445	319	Paramakudi Ramanathapuram	Kadaladi Kamuthi Kilakarai Mudukulathur Paramakudi Rajasingamangalam Ramanathapuram Rameswaram Tiruvadanai	Mudukulathur Paramakudi Ramanathapuram Tiruvadanai	Ramanathapuram
22	Ranipet	RAN	Ranipet	28 November 2019	Vellore	2,234.3	1,210,277	542	Arakkonam Ranipet	Arakkonam Arkadu Kalavai Nemili Sholinghur Walajapet	Arakkonam Arcot Ranipet Sholingur	Arakkonam
23	Salem	SAL	Salem	1 November 1956	None	5,245	3,482,056	669	Attur Mettur Salem Sankagiri	Attur Idappadi Gangavalli Kadayampatti Mettur Omalur Pethanaickenpalayam Salem Salem South Salem West Sankagiri Thalaivasal Vazhapady Yercaud	Attur Edappadi Gangavalli Mettur Omalur Sankari Salem North Salem South Salem West Veerapandi Yercaud	Dharmapuri Kallakkurichi Namakkal Salem
24	Sivaganga	SIV	Sivaganga	15 March 1985	Ramanathapuram	4,086	1,339,101	328	Devakottai Sivaganga	Devakottai Ilayangudi Kalayarkoil Karaikudi Manamadurai Singampunari Sivaganga Tirupathur Tiruppuvanam	Karaikudi Manamadurai Sivaganga Tirupattur	Sivaganga
25	Tenkasi	TEN	Tenkasi	22 November 2019	Tirunelveli	2,916.1	1,407,627	483	Sankarankoil Tenkasi	Alangulam Kadayanallur Sankarankoil Shenkottai Sivagiri Tenkasi Thiruvengadam Veerakeralampudur	Alangulam Kadayanallur Sankarankovil Tenkasi Vasudevanallur	Tenkasi Tirunelveli
26	Thanjavur	THA	Thanjavur	1 November 1956	None	3,396.6	2,405,890	708	Kumbakonam Pattukkottai Thanjavur	Budalur Kumbakonam Orathanadu Papanasam Pattukkottai Peravurani Thanjavur Thiruvaiyaru Thiruvidaimarudur Thiruvonam	Kumbakonam Orathanadu Papanasam Pattukottai Peravurani Thanjavur Thiruvayaru Thiruvidaimarudur	Mayiladuthurai Thanjavur
27	Theni	THE	Theni	25 July 1996	Madurai	3,066	1,245,899	406	Periyakulam Uthamapalayam	Andipatti Bodniayakkanur Theni Periyakulam Uthamapalayam	Andipatti Bodinayakanur Cumbum Periyakulam	Theni
28	Thoothukudi	THO	Thoothukudi	20 October 1986	Tirunelveli	4,621	1,750,176	379	Kovilpatti Tiruchendur Thoothukudi	Eral Ettayapuram Kayatharu Kovilpatti Ottapidaram Sathankulam Thiruvaikundam Tiruchendur Thoothukudi Vilathikulam	Vilathikulam Thoothukudi Tiruchendur Srivaikuntam Ottapidaram Kovilpatti	Thoothukudi
29	Tiruchirappalli	TIC	Tiruchirappalli	1 November 1956	None	4,407	2,722,290	618	Lalgudi Musiri Srirangam Tiruchirappalli	Lalgudi Manachanallur Manapparai Marungapuri Musiri Srirangam Tiruchirappalli West Tiruchirappalli East Thiruverumbur Thottiyam Thuraiyur	Lalgudi Manachanallur Manapparai Musiri Srirangam Thiruverumbur Thuraiyur Tiruchirappalli East Tiruchirappalli West	Karur Perambalur Tiruchirappalli
30	Tirunelveli	TIN	Tirunelveli	1 November 1956	None	3842.4	1,665,253	433	Cheranmahadevi Tirunelveli	Ambasamudram Cheranmahadevi Manur Nanguneri Palayamkottai Radhapuram Tisayanvilai Tirunelveli	Ambasamudram Nanguneri Palayamkottai Radhapuram Tirunelveli	Tirunelveli
31	Tirupathur	TIA	Tirupattur	28 November 2019	Vellore	1,792.9	1,111,812	620	Tirupathur Vaniyambadi	Ambur Natrampalli Tirupathur Vaniyambadi	Ambur Jolarpet Tirupathur Vaniyambadi	Tiruvannamalai Vellore
32	Tiruppur	TIP	Tiruppur	22 February 2009	Coimbatore and Erode	5,186.3	2,479,052	478	Dharapuram Tiruppur Udumalaipettai	Avinashi Dharapuram Kangeyam Madathukulam Palladam Tiruppur North Tiruppur South Udumalaipettai Uthukuli	Avinashi Dharapuram Kangeyam Madathukulam Palladam Tiruppur North Tiruppur South Udumalaipettai	Coimbatore Erode Nilgiris Pollachi Tiruppur
33	Tiruvallur	TAL	Tiruvallur	1 July 1997	Chingleput	3,444.2	3,728,104	1,082	Ponneri Tiruttani Tiruvallur	Avadi Gummidipoondi Pallipattu Ponneri Poonamallee R. K. Pettai Tiruttani Tiruvallur Uthukkottai	Avadi Gummidipoondi Ponneri Poonamallee Tiruttani Tiruvallur	Arakkonam Tiruvallur
34	Tiruvannamalai	TAN	Tiruvannamalai	30 September 1989	North Arcot	6,191	2,464,875	398	Aarani Cheyyar Tiruvannamalai	Aarani Chengam Chetpet Cheyyar Jamunamarathur Kalasapakkam Kilpennathur Polur Thandarampattu Tiruvannamalai Vandavasi Vembakkam	Arani Chengam Cheyyar Kalasapakkam Kilpennathur Polur Tiruvannamalai Vandavasi	Arani Tiruvannamalai
35	Tiruvarur	TAR	Thiruvarur	18 October 1991	Thanjavur	2,161	1,264,277	585	Mannargudi Tiruvarur	Koothanallur Kudavasal Mannargudi Nannilam Needamangalam Thiruthiraipoondi Tiruvarur Valangaiman Muthupet	Mannargudi Nannilam Thiruthuraipoondi Thiruvarur	Nagapattinam Thanjavur
36	Vellore	VEL	Vellore	30 September 1989	North Arcot	2,222.1	1,614,242	726	Gudiyatham Vellore	Anaicut Gudiyatham Pernampattu Katpadi Kilvaithinankuppam Vellore	Anaikattu Gudiyatham Katpadi Kilvaithinankuppam Vellore	Arakkonam Vellore
37	Viluppuram	VIL	Viluppuram	30 September 1993	South Arcot	3,725.5	2,093,003	562	Tindivanam Villupuram	Gingee Kandachipuram Marakkanam Melmalaianur Tindivanam Vanur Vikravandi Villupuram Thiruvennainallur	Gingee Mailam Tindivanam Vanur Villupuram Vikravandi	Arani Villupuram
38	Virudhunagar	VIR	Virudhunagar	15 March 1985	Ramanathapuram	4,288.0	1,942,288	453	Aruppukkottai Sattur Sivakasi	Aruppukkottai Kariapatti Rajapalayam Sattur Sivakasi Srivilliputhur Tiruchuli Virudhunagar Watrap Vembakottai	Aruppukkottai Rajapalayam Sattur Sivakasi Srivilliputhur Tiruchuli Virudhunagar	Ramanathapuram Tenkasi Virudhunagar

Former districts edit

• List of developmental administrative units of Tamil Nadu
• List of revenue divisions of Tamil Nadu
• List of districts in Tamil Nadu by Human Development Index