Thiruvarur district is a district of Tamil Nadu state with its administrative headquarters located at Thiruvarur town. Earlier, the historic town was known as Aaroor (Arur). It is mentioned in the 7th century Saiva canonical work, Tevaram. The term Thiru is inscripted in almost all the temples of the place which are mostly admired by the verses of Tevaram. Due to this very reason the name of the place was changed from Arur to Thiruvarur. The place Thiruvarur has also another name i.e. Kamalayaksetra means “the holy place that has an abode of lotuses”. The town is also known as so because of the Kamalayayam tank and the temple deity, Kamalambigai. During the British Rule, the town was termed as Tiruvalur, Tiruvaloor and Thiruvalur. Till 1991 Thiruvarur was a part of Thanjavur district.  On 1st January, 1997 Thiruvarur was emerged as separate district. Kailasam Balachander, an illustrious Indian director, producer, writer, actor, playwright, stage conductor, and comedian was born on 9th July, 1930 in Tanjore district, British India (now Tiruvarur district, Tamil Nadu). For his contribution to the tamil film industry he was honoured by many great awards namely Kalaimamani Award, Padma Shri Award, Dadasaheb Phalke Award and ANR National Award.

Geographically the district lies at 10°77'N latitude, 79°64'E longitude and 10 m altitude. In the year 2021, there was a total 3.08% forest area of total geographical area. The district occupies a geographical area of 2,274 sq. km. and it is bounded by Nagapattinam district on the east, Thanjavur District on the west and the Palk Strait on the south. Vennar and Vettar, the tributaries of river Cauvery are the principal water bodies of the district. The natives of the district experience tropical climate during summer i.e. from March to May. The actual rainfall in the district was 1587.3 mm in the year of 2021-22.

To administer in a better way the district is divided into 7 tehsils-Kudavasal, Mannargudi, Nannilam, Needamangalam, Thiruthuraipoondi, Thiruvarur and Valangaiman. Moreover, there are 2 revenue divisions, 10 blocks and 4 municipalities.

As per 2011 census the district has a population of 12,64,277 (persons) out of which 6,26,693 (males) and 6,37,584 (females). The district has a sex ratio of 1,144 females for every 1000 males. In the year 2001-2011 the population growth rate of the district was 8.11 (persons), 7.90 (males) and 8.31 (females). As per 2011 census the major religion of the district is Hindu with 89.99% of the total population. According to 2011 census the principal language in the district is Tamil with 99.40%. In the year 2020 the number of live births in the district was 13,865 out of which 7,111 were males and 6,754 were females. In the same year the number of deaths in the district was 11,761 out of which 6,972 were males and 4,789 were females.

Agriculture is the prime livelihood for the people of the district. More than 70% of the population of the district are engaged in agriculture. Paddy is the core crop of the district. Besides paddy cultivation, goat rearing, dairy, coir making and handicrafts are the other important activities of the district. The district has some small enterprises also like automobile servicing, hotels, hospitals, boat repairing and nylon fishnet repairing. In the year 2011-12 the gross domestic product in the district was Rs. 6,47,411 lakhs at current price and Rs. 4,16,363 lakhs at constant prices in the year 2004-2005. The net domestic product in the district during the period 2018-19 was Rs. 13,76,844 lakh at current price and Rs. 9,82,072 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. 74,099 at current price and Rs. 54,031 at constant prices in the year 2011-2012.

According to 2011 census the literacy rate of the district is 82.86% (persons), 89.13% (males) and 76.72% (females). The literacy rate of the district is low as compared to the other districts of the state. The Central University of Tamil Nadu, established in the year 2009 by an act of parliament offers several courses in the streams of arts and science. Most of the colleges in the district are affiliated to this university.

Kalyanasundaram Anbazhagan, a veteran politician and the former finance minister of Tamil Nadu was born on 19th December, 1922 in Kattoor near Thiruvarur, Thiruvarur District. He is a member of Dravida Munnetra Kazhagam (DMK) political party. Thalikottai Rajuthevar Baalu, a renowned Tamil politician was born on 15th June, 1941 in Thalikottai of the district. He is a member of the DMK political party. He held many vital political portfolios in different years.

The district has many centres of attraction which allures travellers from different parts of the country as well world. Alangudi, a place to worship Guru, one of the navagrahas is situated on the Kumbakonam–Valangaiman road. Koothanur is situated at a distance of 21 km. from Thiruvarur. Arulmighu Maha Saraswathy Amman temple is the identity of the place. Eekan, a village on the Thiruvarur - Thanjavur road is famous for the Arulmighu Subramanya Swamy temple. Shri Raja Gopalaswamy temple is considered as the king of the temples in the Tamil Nadu state. This temple is also called as the Kulothunga Cholan Vinnagaram, in memory of its builder. Valangaiman Varatharajan Pettai Maha Mariamman temple is situated 9 km. away from Kumbakonam. This temple is also known as Paadaikavadi Mariamman. Muthupettai Dargah, a seven hundred years old Dargah is popularly known as Andavar Shahul Dawood Khamil Oliyullh which was constructed by using Mahratta architecture. The district has also some prominent forests and birds sanctuaries like Muthupettai Mangrove Forest, Udhayamarthadapuram Birds Sanctuary, Vaduvoor Birds Sanctuary, etc.