Thrissur district is a district of Kerala state with its administrative headquarters located at Thrissur city. The district got its name from the Tamil/Malayalam term 'Thiru-Shiva-Perur' meaning "The city with the name of the Lord Siva". During the ancient time the district was popularly called as "Vrishabhadripuram" and "Kailasam". Some other believes that the meaning of the term 'Thri-shiva-peroor' is the big land with three Shiva temples, the three prominent Shiva temples namely Vadakkunnathan temple, Asokeswaram Siva temple and Irattachira Siva temple. From the very beginning, Thrissur district has played significant role in the political history of South India. Prior to independence when the entire Thrissur used to come under the Madras dynasty at that time there are many Tamil speaking families there. Its early political history is closely associated with that of the Cheras of the Sangam age, who ruled over a huge part of Kerala and their capital, Vanchi as well. The whole of the today’s Thrissur district was included in the early Chera Empire. On 1st January, 1956 the Thrissur district was emerged as a separate district in the map of Kerala.

Nalapat Balamani Amma, an eminent Indian poet who wrote mostly in Malayalam was born on 19th July, 1909 at Punnayurkulam in the district. Some of her most admired works are Amma, Muthassi and Mazhuvinte Katha. She was honoured by of many prestigious awards namely Padma Bhushan, Saraswati Samman, Sahitya Akademi Award and Ezhuthachan Award. Kakkadan Nandanath Raj, a distinguished Indian economist who played a vital role in India's planned development and drafting sections of its first Five Year Plan was born on 13th May, 1924 in the Thrissur district. He was served as an advisor to several Prime Ministers from Jawaharlal Nehru to P.V. Narasimha Rao. The Government of India honoured him by the great Padma Vibhushan Award in 2000.

Geographically, the district lies at 10°52'N latitude, 76°22'E longitude and 3 m Altitude. In the year 2021, there was a total 38.53% forest area of total geographical area. The district encompasses an area of 3,027 sq km. and it is bounded by Malappuram district on the north, Ernakulam district on the south, Palakkad district on the east and the Arabian Sea on the west. Generally, the climate of the district remains hot and humid. Most of its rainfall occurs in the monsoon season. The actual rainfall in the district was 3459.7 mm in the year of 2021-22.

Administration wise, the district is divided into 6 taluks including Thrissur, Mukundapuram, Kodungallur, Chavakad, Thalapilly and Chalakudy. There are 2 Lok Sabha and 13 Assembly constituencies in the district. Moreover, the district comprises 135 towns and 98 villages. The administrative language in the district is Malayalam.

According to 2011 census the district has a population of 31,21,200 out of which 14,80,763 are males and 16,40,437 are females. The district has a sex ratio of 1108 females for every 1000 males. In the year 2001-2011 the population growth rate in the district was 4.94% including 4.13% were males and 5.69% were females. As per 2011 census the major religions in the district are Hindu and Christian with 58.42% and 24.27% of the total population. The population density in the district is 1,031 persons per sq. km. According to 2011 census the principal language in the district is Malayalam with 98.91%. In the year 2020 the number of live births in the district was 41,979 out of which 21,338 were males and 20,636 were females. In the same year the number of deaths in the district was 28,472 out of which 15,296 were males and 13,175 were females.

The power loom industry and textile mills of the Thrissur district are very famous. Some of its chief industries are Kerala Lakshmi Mills, Thrissur Cotton Mills, Rajgopal Textiles, Vanaga Textiles, Darlco Cannings, Kayee Plantations Cannings, etc. The district is developing as a centre for Ayurvedic drug manufacturing industry in the India. The plain gold and rolled gold jewelleries manufactured in the district are very popular throughout the country. Every year a huge chunk of revenue comes from these industries help in its economy to a great extent. In the year 2020-21 the gross domestic product in the district was Rs. 67,88,122 lakhs at current price and Rs. 43,60,703 lakhs at constant prices in the year 2011-2012. The net domestic product in the district during the period 2020-21 was Rs. 60,91,231 lakh at current price and Rs. 39,71,552 lakh at constant prices in the year 2011-2012. The Per Capita Income or NDDP, At Factor Cost during the period 2020-21 was Rs. 1,86,416 at current price and Rs. 1,21,546 at constant prices in the year 2011-2012.

The district provides a platform for higher education. It was an important seat of Sanskrit learning during the ancient days. Generally the medium of instructions in the school of the district are English and Malayalam. Some of its reputed educational institutions are Kerala Kalamandalam, Kerala Police Academy, Kerala Agricultural University, Kerala University of Medical and Allied Sciences, National Research Institute for Panchakarma, Kerala Institute of Local Administration, etc. As per 2011 census the literacy rate in the district is 95.08% including 96.78% are males and 93.56% are females. The total number of literates in the district is 26,78,548 including 12,82,261 are males and 13,96,287 are females.

Chelat Achutha Menon, an illustrious Indian politician and the Chief Minister of Kerala state for two terms i.e. 1st November, 1969 to 1st August, 1970 and 4th October, 1970 to 25th March, 1977 was born on 13st January, 1913 at Puthukkad in the district. He was a member of Communist Party of India (political party). K. P. Rajendran, a renowned Indian politician, State Executive Member of Communist Party of India and National Working Committee Member of All India Trade Union Congress (AITUC) was born on 3rd November, 1954 in the Thrissur district. He was also served as the Minister for Revenue and Land Reforms under the Government of Kerala from 2006-2011.

During the year June 2021, there were 2,57,782 domestic tourists and 60 foreign tourists. Every year many travellers from different parts of the world come to the Thrissur district to enjoy its great variety of tourist places. Athirappilly, located at a distance of 60 km. from Thrissur city is a perfect tourist location. Athirappilly Falls, an 80 feet high waterfall at the verge of the Sholayar ranges is a well-liked picnic spot and recreation. There are also two very nice amusement parks located in the nearby place are Dream World and Silver Storm. Vazhachal Falls, situated just 5 km. from entrance of Athirappilly Falls is an ideal destination for nature’s lovers. Punnathurkotta, a wonderful fort and a palace is situated in Kottapadi in the Thrissur district. Within the Punnathurkotta there is an elephant camp with over 60 elephants which is also a training school of elephants. The district has some notable dams such as Peechi Dam, Poomala Dam, Vazhani Dam, Chimmony dam, etc. The locations of dams are occasionally use by people as picnic spots.