The name Kottayam is derived from two Malayalam words kott means fort and akammm means inside, the two Malayalam terms together means "the interior of the fort". During the British period in India, Kottayam was a part of the Princely State of Travancore. At that time, Kottayam has played a vital role in almost all the freedom movements. The notable 'Malayali Memorial' agitation perhaps had its origin in the place of Kottayam. The Malayali Memorial sought to secure better representation for educated Travancoreans in the Travancore civil service against persons from outside. In 1868, Kottayam was formed as a revenue division in Travancore. In 1949, when the integration of the State of Travancore and Cochin was taken place, the revenue divisions were renamed as districts. Therefore, in July 1949, Kottayam was emerged as a separate district.

Vaikom Muhammad Basheer, a famous Malayalam fiction writer, a humanist, freedom fighter, novelist and short story writer was born on 21st January, 1908 at Thalayolaparambu in the district. In the year 1982 he was honoured by the Padma Shri Award. Joseph Ganapathiplackal Abraham, a well known Indian track and field athlete was born on 11th September, 1981 in Kottayam district of Kerala. He won gold medal in 400m hurdles for two times at 2005 All-India Open National Championships and 2010 Guangzhou Asian Games.

Geographically the district lies at 9°60'N latitudes, 76°53'E longitudes and 3 m Altitude. In the year 2021, there was a total 49.82% forest area of total geographical area. The district occupies a geographical area of 2,206 sq km. and it is surrounded by Pathanamthitta district on the south, Alappuzha district on the west, Ernakulam district on the north and Idukki district on the east. The principal rivers of the district are the Meenachil River, the Muvattupuzha River and the Manimala River. Annual temperatures range of the district is between 20 to 35 °C (68 to 95 °F). Most of its rainfall occurs in the monsoon season. The actual rainfall in the district was 4443.6 mm in the year of 2021-22.

Administrative wise, the district consists of 5 taluks (tehsils)-Kottayam, Changanassery, Vaikom, Kanjirappally and Meenachil. To administer in a better way the district is divided into two revenue divisions-Kottayam and Pala. Moreover, the district comprises 17 towns and 80 villages. The administrative language in the district is Malayalam.

As per 2011 census the district has a population of 19,74,551 out of which 9,68,289 are males and 10,06,262 are females. The district has a sex ratio of 1,039 (females for every 1000 males). In the year 2001-2011 the population growth rate of the district was 1.07% including 0.35% are males and 1.77% are females. According to 2011 census the major religions of the district are Hindu and Christian with 49.81% and 43.48% of the total population. The population density in the district is 895 persons per sq. km. As per 2011 census the principal language in the district is Malayalam with 98.88%. In the year 2020 the number of live births in the district was 22,371 out of which 11,311 were males and 11,058 were females. In the same year the number of deaths in the district was 18,788 out of which 10,775 were males and 8,012 were females.

The great chunks of revenue of the district come from the rubber production and spices cultivation. The Rubber Board, a body set up by the Government of India for the development of the rubber industry, is located at Kottayam. The Plantation Corporation of Kerala has its headquarters at Kottayam. The industries of the district are Hindustan Newsprint Limited, Kottayam Spinning Mills and KSE factory. Tourism is one of the foremost sources of economy of the district. In the year 2020-21 the gross domestic product in the district was Rs. 41,83,305 lakhs at current price and Rs. 27,90,704 lakhs at constant prices in the year 2011-2012. The net domestic product in the district during the period 2020-21 was Rs. 36,52,409 lakh at current price and Rs. 24,96,297 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. 1,83,113 at current price and Rs. 1,25,152 at constant prices in the year 2011-2012.

C.M.S College, the first college of Kerala was started at Kottayam in 1840. Mahatma Gandhi University, one of the six universities in Kerala is located here. Rajiv Gandhi Institute of Technology, a government engineering college which is named after the name of former prime minister of India Mr. Rajiv Gandhi is situated in Pampady. As per 2011 census the literacy rate in the district is 97.21% out of which 97.97% are males and 96.48% are females. The total number of literates in the district is 17,49,798 including 8,61,592 are males and 8,88,206 are females.

Kocheril Raman Narayanan, former president of India was born on 27th October, 1920 at Uzhavoor village, in the district. He was the member of India National Congress. In 1992 he was elected as the ninth Vice President of India. In 1997 he became the President of India. Oommen Chandy, a veteran Indian politician and the present Chief Minister of Kerala since May, 2011 was born on 31th October, 1943 in Kumarakom, Kottayam district. Earlier, also he was the Chief Minister of Kerala from 2004 to 2006. He is the member of Indian National Congress.

During the year June 2021, there were 55,616 domestic tourists and 67 foreign tourists. Kottayam is one of the vital tourist places to visit in India. The Vembanad Lake is located 16 km away from Kottayam town. During Onam with a spectacular water regatta the serene lake comes alive. Kumarakom Bird Sanctuary, located on the banks of the Vembanad Lake is 16 km from Kottayam town. Pathiramanal, Nattakom and Panachikad are the prominent places of the district where the migratory birds can be found. Elaveezha poonchira, a hill station near Melukavu Mattom is located 60kms away from Kottayam. The three beautiful hillocks in the place are Mankunnu, Kudayathoormala and Thonippara. The Poonjar Palace of the district is the glorious evidence to the royal lavishness of a bygone era. In the palace there is an extraordinary regal collection of antiques and exquisite furnitures. Wagamon, an enchanting hill station is situated 64 kms from Kottayam. This enchanting hill station on the Idukki-Kottayam border dotted with tea gardens and meadows. The Thazhathangadi Juma Masjid of the district is one of the oldest mosques in India (about 1,000 years old). Natives believe that Habib Dinar (son of Malik Dinar who introduced Kerala to Islam) constructed the masjid. It is built in the traditional Kerala style of architecture.