Thoothukudi district is a district of the Tamil Nadu state with its administrative headquarters located at Thoothukudi town. The district got its name from its headquarters town, Toothukudi. Earlier the place was popularly known as Tuticorin. The region is also well known by one more name i.e. Muthu Kuzhithurai. Since the state of Tamil Nadu starts from this place hence it is also called as "Sea Gateway of Tamil Nadu". Thoothukudi is part of the Pearl Fishery Coast and renowned for its pearl fishing and shipbuilding industries. Thoothukudi remained in the hands of the Cholas during the period between 9^th and 12^th century. In the 16^th century the place was under the rule of Portuguese but the Dutch took over it from Portuguese in the 17^th century. Finally, the British came and captured the place of Thoothukudi from the Dutch in 1782. on the other hand the East India Company established their control over Thoothukudi in the same year. Then Thoothukudi came out as the citadel of freedom struggle in the early of the 20^th century. It was the place Thoothukudi where the illustrious patriot named V.O. Chidambaram established the first swadesi Stream Navigation Company, sailing the first steamer, S.S. Gaelia to Thoothukudi on 1^st June, 1907. Since from that period they used it as a port and in 1866 they gave it the status of a municipality. Previously, the place Thoothukudi was a part of the former Tirunelveli district but Thoothukudi was carved out from it and emerged as a separate district in the map of Tamil Nadu state on 20^th October, 1986.

Valliappan Olaganathan Chidambaram Pillai, a veteran Tamil political leader, freedom fighter and a disciple of Bal Gangadhar Tilak was born on 5^th September, 1872 at Ottapidaram in the district. He was popularly known as Kappalottiya Tamilan meaning "The Tamil Helmsman".

Geographically, the district lies at 08°76'N latitude, 78°13'E longitude and 4 m altitude. In the year 2021, there was a total 5.31% forest area of total geographical area. The district encompasses a geographical area of 4,745 sq. km. and it is bounded by Virudhunagar district and Ramanathapuram district on the North, Bay of Bengal on the South and South East and Tirunelveli district on the West and South West. Most of its rainfall occurs in the monsoon season. The actual rainfall in the district was 791.5 mm in the year of 2021-22.

Administration wise, the district is divided into 8 talukas namely Ettayapuram, Kovilpatti, Ottapidaram, Sathankulam, Srivaikundam, Thoothukkudi, Tiruchendur and Vilathikulam. Moreover, it comprises 35 towns and 439 villages. The administrative language in the district is Tamil.

According to 211 census the district has a population of 17,50,176 out of which 8,65,021 are males and 8,85,155 are females. The district has a sex ratio of 1023 (females for every 1000 males). During the year 2001-2011 the population growth rate in the district was 11.32% including 12.81% were males and 9.90% were females. As per 2011 census the major religion in the district is Hindu with 78.50% of the total population. The population density in the district is 369 persons per sq. km. According to 2011 census the principal language in the district is Tamil with 97.00%. In the year 2020 the number of live births in the district was 22,629 out of which 11,608 were males and 11,021 were females. In the same year the number of deaths in the district was 16,341 out of which 9,347 were males and 6,994 were females.

Salt pan of the district is the backbone of the economy of the district. Every year these salt pans of the district produce a huge quantity of salts which upgrade Tamil Nadu as the second largest salt producer state in India next to Gujarat. The other prime industries in the district are shipping, fishing, agricultural, power and chemical industries, etc. More than half of its population are directly or indirectly engaged in these industries in order to earn their livelihood. Fishing is one of the largest contributors to its local economy. The economy of the district is also dependent on the agricultural sector to a great extent. The chief agricultural products in the district are paddy, pulses, cotton, groundnut, etc. The adoption of the new agricultural technologies amongst the farmers of the district helps to increase the production of various agricultural items. In the year 2011-12 the gross domestic product in the district was Rs. 18,85,940 lakhs at current price and Rs. 12,28,778 lakhs at constant prices in the year 2004-2005. The net domestic product in the district during the period 2018-19 was Rs. 35,75,175 lakh at current price and Rs. 25,15,149 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. 15,120 at current price and Rs. 1,14,009 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. Most of the colleges in the district are affiliated to the Manonmaniam Sundaranar University in Tirunelveli. As per 2011 census the literacy rate in the district is 86.16% including 91.14% are males and 81.33% are females. The total number of literates in the district is 13,49,697 including 7,03,106 are males and 6,46,591 are females.

S.R. Jeyadurai, an eminent Indian politician and a member of the 15^th Lok Sabha from the Thoothukudi Constituency was born on 19^th March, 1969 at Mangalapuram in the Thoothukudi district. He is a member of the Dravida Munnetra Kazhagam party.

The district has several centres of attraction which allures many travellers from different parts of the country as well as world. Tiruchendur, situated in the Thoothukudi district is the most significant tourist destination. This place has one of the six abodes of Lord Murugan which is called Arupadai Veedu. Pilgrims from far off places comes to this place to offer their prayers. Srivaikuntam and Alwarthiru-nagari, situated in the district are the two prominent Vaishnavaite shrines. The place is also popularly known as Kailasapuram. Nava Thiruppathis, a sacred place which comprises the nine holy shrines of Lord Vishnu is located in the Thoothukudi district. Some other notable places of interest in the district are Panchalamkurichi, Ettaiyapuram, Manappadu, etc.