Historically, it is believed that during the 14th century CE the district was founded by Amba Rajput. According to another theory the name is a corruption of Amba Wala meaning the mango village. Ambala Cantonment is location of historic Ambala European Cemetery. In the year 1843 Ambala Cantonment was set up when the British were forced to leave its Karnal Cantonment after the malaria epidemic of 1841-42 since at that time no effective measures were available to control malaria epidemic in those days. Ambala was emerged as a separate district in 1843. From the very beginning till today, the place of Ambala has witnessed many changes in its territorial boundaries. Ambala Air Force Base is one of the oldest and largest airbases that were inherited from the British by the IAF.

Prem Chandra Dhanda (1911-2013) was an Indian physician, a medical academic and the Principal of the Maulana Azad Medical College. In 1962, he was awarded with the Padma Bhushan for his contribution in the field of medicine. Sunita Jain is scholar, novelist, short-story writer and poet in English and Hindi literature. She has served as a professor and the head of the department of Humanities and Social Sciences in the Indian Institute of Technology in Delhi. She has written more than 60 books. She has rewarded by The Vreeland Award in 1969 and the Marie Sandoz Prairie Schooner Fiction Award in 1970 and 1971 and the Padma Shri in 2004. She also got place in the Encyclopedia of Post-Colonial Literatures in English. Roshan Kumari Fakir Mohammad is a well known Indian classical dancer from Jaipur Gharana, actor and choreographer. She established the Nritya Kala Kendra in Mumbai. She was awarded with Sangeet Natak Akademi Award in 1975 and the Padam Shri in 1984.

Geographically, the district has a total 1,574 sq. km. area and occupies the rank 14th in State and 558th in India on the bases of this size. It lies at 30°38'N latitude, 76°78'E longitude and 264 m altitude. In the year 2021, there was a total 3.32% forest area of total geographical area. It is bounded by Yamunanagar to the East, district Sirmaur and district Panchkula to the North, district Mohali and Patiala district to the West, and Kurukshetra district to the South. It is located in Indo-Gangatic plain. The actual rainfall in the district was 825.3 mm in the year of 2021-22.

Administrative wise, the district is divided into 3 sub-districts, 15 towns and 470 villages. Hindi is its official language. In the state of Haryana with an allotted district code of 70th district of Ambala came into existence in the year 1843 with its headquarters located at Ambala which is situated at a distance of 45 kms. from the State Capital, Chandigarh.

Demographically, according to the 2011 census, the district has a total number of 2,08,071 households with a total population of 11,28,350 comprising 5,98,703 are males and 5,29,647 are females which causing it to occupy the ranks of 11th in the state and 410th in the whole of India. The density of population of the district is 717 persons per sq. km. The sex ratio is pegged at 885 females per every 1000 males while the child ratio stands at 810 females per every 1000 males. As per 2011 census the major religions in the district are Hindu and Sikh with 84.65% and 12.25% of the total population. According to the 2011 census, the percentage of the principal languages in the district are Hindi at 87.72% and Punjabi at 10.96%. In the year 2020 the number of live births in the district was 21,330 out of which 11,073 were males and 10,257 were females. In the same year the number of deaths in the district was 10,562 out of which 6,347 were males and 4,215 were females. The population growth rate during the period 2001 to 2011 was 11.23% including 10.26% were males and 12.35% were females.

Economically, the district is mainly dependent on the agriculture. The land of the district is very fertile. It produces scientific and surgical instruments on the large scale. A number of small scale industries are also available. Industries related to the manufacturing of submersible pumps and mixers and grinders are being flourished here. It also has a well known market for cloths. The GDDP or Gross District Domestic Product during the period 2005-06 was Rs. 5,52,847 lakh at Current Price and Rs. 4,34,867 lakh at Constant Prices during the period 1999-2000. The NDDP, or Net District Domestic Product during the period 2005-06 was Rs. 5,15,280 lakh at Current Price and Rs. 4,07,360 at Constant Prices during the year 1999-2000. The Per Capita Income or NDDP, at factor cost during the year 2011-12 was Rs. 1,16,329 lakh at Current Price during the year 2004-2005.

Education wise, according to the 2011 census, the literacy rate in the district is 81.75% including 87.34% are males and 75.5% are females. The total literate population of the district is 8,18,025 comprising 4,61,288 are males and 3,56,737 are females. The district has several educational institutes including schools and colleges. The name of some of the well known schools is S.A. Jain Senior Secondary School, Tulsi Public Senior Secondary School, S.A. Jain Senior Model School, P.K.R Jain Girls Senior Secondary School, D.A.V. Public School. There are 2 polytechnics in Ambala city for technical education. A number of primary, secondary and higher secondary schools are also located in Ambala Cantt such as Farouche Khalsa Sr. sec. school, D.A.V. Sr. Sec. School, Riverside D.A.V. Sr. sec. school, B.D. Sr. Secondary School (Affiliated to Haryana Board of Education). Several institutes offer skill based job oriented courses for instance ICA, ARC Web designing and graphic designing institute, TCIL, etc.

Sushma Swaraj (born 14th February, 1952) is an Indian politician from Bhartiya Janta Party. She is the current Minister of External Affairs of India since 26th May, 2014. She became the youngest cabinet minister at the age of 25 in 1977 and 5th Chief Minister of Delhi for a brief term in 1998. She was the youngest cabinet minister of north Indian state of Haryana. Satwinder Kaur Dhaliwal was born on 17th June, 1953. She is a political and social worker. She belongs to Shiromani Akali Dal. She represented the Ropar constituency in the Parliament. In 1997, she served as a Member on the Committee on Agriculture in the 11th Lok Sabha. In 1998, she served as a member of the Committee on Railways, member of the Committee on Members of Parliament Local Area Development Scheme and member of Consultative Committee of Ministry of Social Justice and Empowerment in the 12th Lok Sabha.

The district has numerous famous historical and religious places to visit. These places are Bhawani Amba Temple, Kali Mata Mandir, The Badshahi Bag Gurdwara, Sis Ganj Gurdwara, Manji Sahib Gurdwara and Sangat Sahib Gurdwara, Popular Muslim Shrines of Lakhi Shah and Taqwal Shah, Saint Paul's Church and An Old British Christian Cemetery, Patel Park, City Park. In the year 2020-2021, there were total 4,999 domestic tourists.