List of prime ministers of Sri Lanka From 1947-2023 – First Prime Minister – The prime minister’s post in the Sri Lankan government was created in 1947, a few months before Ceylon (sri lanka’s former name) was granted independence as the dominion of ceylon. The status of dominance within the British Commonwealth was retained for the next 24 years until May 22, 1972, when it became a republic and was renamed as the Republic of Sri Lanka. The Prime Minister of Ceylon was the head of government until 1972. When Sri Lanka became a republic, the post became known as the Prime Minister of Sri Lanka. The Prime Minister also held the Unified Ministry of External Affairs and the Ministry of Defence until 1977, when the government of J.R. Jayawardene adopted two ministries, the Ministry of Defence and the Ministry of External Affairs.
List of prime ministers of Sri Lanka From 1947-2023 – First Prime Minister
| Prime Minister Name | Tenure |
| Don Stephen Senanayake |  24 September 1947 – 22 March 1952 |
| Dudley Senanayake | 26 March 1952 – 12 October 1953 |
| Sir John Kotelawala |  12 October 1953 – 12 April 1956 |
| S.W.R.D. Bandaranaike |  12 April 1956 – 26 September 1959 |
| Wijeyananda Dahanayake |  26 September 1959 – 20 March 1960 |
| Dudley Senanayake |  21 March 1960 – 21 July 1960 |
| Sirimavo Bandaranayake |  21 July 1960 – 25 March 1965 |
| Dudley Senanayake |  25 March 1965 – 29 May 1970 |
| Sirimavo Bandaranayake |  29 May 1970 – 23 July 1977 |
| Junius Richard Jayewardene |  23 July 1977 – 4 February 1978 |
| Ranasinghe Premadasa |  6 February 1978 – 2 January 1989 |
| Dingiri Banda Wijetunga |  6 March 1989 – 7 May 1993 |
| Ranil Wickremesinghe |  7 May 1993 – 19 August 1994 |
| Chandrika Kumaratunga |  19 August 1994 – 12 November 1994 |
| Sirimavo Bandaranayake |  14 November 1994 – 9 August 2000 |
| Ratnasiri Wickremanayake |  10 August 2000 – 7 December 2001 |
| Ranil Wickremesinghe |  9 December 2001 – 6 April 2004 |
| Mahinda Rajapaksa |  6 April 2004 – 19 November 2005 |
| Ratnasiri Wickremanayake |  19 November 2005 – 21 April 2010 |
| D. M. Jayaratne |  21 April 2010 – 9 January 2015 |
| Ranil Wickremesinghe | 9 January 2015 – 26 October 2018 |
| Mahinda Rajapaksa | 26 October 2018 – 15 December 2018 |
| Ranil Wickremesinghe | 16 December 2018 – 21 November 2019 |
| Mahinda Rajapaksa | 21 November 2019 – 9 May 2022 |
| Ranil Wickremesinghe | 12 May 2022 – 9 July 2022 |
- The Prime Minister leads the Cabinet affairs and also acts as a deputy to the President.
- If a President dies in office, the Prime Minister becomes the acting President until the Parliament elects a successor or new elections can be held to elect a new President.
- In 1993, the then President Ranasinghe Premadasa was assassinated and Prime Minister Dingiri Banda Wijetunge took office as President.
- On April 28, 2015, the Parliament approved the Nineteenth Amendment to the Constitution of Sri Lanka which gives the power of the government to the Prime Minister, while the President remains the head of state, head of the Cabinet, and Commander-in-chief.
- Ranil Wickramasinghe has become the Prime Minister the most number of times.
- Dudley Shelton Senanayaka and Sirimavo Bandaranayake have been appointed three times.
- Mahinda Rajapaksa remains the only Prime Minister to be suspended from his duties by a Lankan court.
- List of Presidents of Sri Lanka From 1972-2022 – First President
