Theni district is a district of Tamil Nadu state with its administrative headquarters located at Theni town. It is believed that the area covered by present day’s Theni district was very thinly populated prior to the 1900s. In the year 1886 Mullaperiyar dam project bought some portion of the water from the Periyar River downhill to the Cumbum Valley and then merged it into the Mullayar River. This project encouraged some more people to come and settle down in the Cumbum Valley. Theni was not a popular town earlier but it came into limelight by the 1900s. After the Mullay-Periyaar merger project lots of people from nearby dry arid regions likewise Sivakasi, Kovilpatti, Virudhunagar, Sattur and several other nearby towns settled in the valley of Cumbum (today’s Theni district). Thus, there was influx of people in this region by the 1890s to 1920s. After sometime Theni developed rapidly due to lots of business activities. In the beginning, Theni was a part of the Madurai district but then Theni was bifurcated and emerged as a separate district on July 7, 1996. As a result the newly formed Theni district comprised one new Revenue Division and two new taluks namely Theni and Bodinayakanur with headquarters located at Uthamapalayam which were created and effective from 1st January, 1997. Until 31st December, 1996 Theni Municipal town was only a firka or revenue block headquarters. After sometime, Theni Municipal Town was uplifted as the Taluk and then on 1st January, 1997 it became the district headquarters.

P. Bharathiraja, an eminent Indian filmmaker who works mainly in the Tamil film industry was born on 17th July, 1941 at Alli Nagaram in the Theni district. The Government of India honoured him with the prestigious Padma Shri Award in 2004 for his contribution to Cinema.

Geographically, the district lies at 10°01'N latitude, 77°48'E longitude and 303 m altitude. In the year 2021, there was a total 41.28% forest area of total geographical area. The district encompasses a geographical area of 2,868 sq. km. and it is bounded by Dindigul district on the North, Virudhunagar district on the South West, Madurai district on the East and Idukki district of Kerala on the West. The climate of the district is characterised as salubrious climate. Most of its rainfall occurs in the monsoon season. The actual rainfall in the district was 1170.2 mm in the year of 2021-22.

Administration wise, the district is divided into 5 talukas namely Periyakulam, Theni, Andipatti, Uthamapalayam and Bodinayakanur. Moreover, it comprises 28 towns and 98 villages. The administrative language in the district is Tamil.

According to 2011 census the district has a population of 12,45,899 out of which 6,25,683 are males and 6,20,216 are females. The district has a sex ratio of 991 (females for every 1000 males). During the year 2001-2011 the population growth rate in the district was 13.89% including 13.15% were males and 14.65% were females. As per 2011 census the major religion in the district is Hindu with 92.22% of the total population. The population density in the district was 434 persons per sq. km. According to 2011 census the principal language in the district is Tamil with 79.04%. In the year 2020 the number of live births in the district was 16,640 out of which 8,479 were males and 8,161 were females. In the same year the number of deaths in the district was 12,776 out of which 7,566 were males and 5,210 were females.

Agriculture is the backbone of the economy of the district. Most of the lands in the district are use for agricultural purposes. More than half of its population are engaged in agriculture in order to earn their livelihood. The chief agricultural products in the district are Paddy, cholam, cumbu, red gram, green gram, black gram, horse gram, turmeric, mango, banana, tapiaco, groundnut, gingerly, sugarcane, tamarind, cashew, etc. Cumbam Valley is one of the biggest grape producer regions in the district. The district is scantily industrialised but it is rich is forestry based industry. Additionally, every year a huge chunk of revenue comes from the tourism sector of the district helps in its economy to a great extent. In the year 2011-12 the gross domestic product in the district was Rs. 7,35,038 lakhs at current price and Rs. 4,37,551 lakhs at constant prices in the year 2004-2005. The net domestic product in the district during the period 2018-19 was Rs. 17,08,581 lakh at current price and Rs. 11,75,580 lakh at constant prices in the year 2011-2012. The Per Capita Income or NDDP, At Factor Cost during the period 2016-17 was Rs. 1,05,789 at current price and Rs. 76,430 at constant prices in the year 2011-2012.

The district is well known as an abode of several reputed educational institutions. It provides a platform for higher education. Some of its recognised educational institutions are Madurai Kamraj University College, Nadar Saraswathi College of Engineering and Technology, VPV College of Engineering, Government Theni Medical College, College of Agricultural Technology, Bharath Niketan engineering College, Odiyappa College of Engineering and Technology, etc. As per 2011 census the literacy rate in the district is 77.26% including 85.03% are males and 69.46% are females. The total number of literates in the district is 8,70,080 out of which 4,79,403 are males and 3,90,677 are females.

The district has several centres of attraction which allures many travellers from different parts of the country as well as world. Vaigai Dam, located near Andipatti in the Theni district is constructed across the Vaigai River. It provides water for irrigation to the districts of Madurai and Dindigul as well as drinking water to Madurai and Andipatti. Suruli falls, located at a distance of 56 km. from Theni is a 2 stage Cascading water fall which falls drop from a height of 150 feet (46 m). Meghamalai, popularly known as High Wavy Mountains is a wonderful, cool and misty mountain range situated at an elevation of 1,500 m above sea level in the Western Ghats of the Theni district. It is a place full of mesmerising natural beauty dotted with cardamom plantations and tea estates. Some of its other notable places of interest are Kumbakkarai Falls, Shanmuganathi Dam, Manjalar Dam, etc.