The Ninth Parliament of Sri Lanka, which began on August 20, 2020, and was dissolved by the President at midnight on September 24, 2024, saw a total of 390 days of sessions across five distinct periods. Throughout its tenure, the Parliament faced significant changes, including 19 vacancies filled by the appointment of 16 new Members of Parliament on 18 occasions.

The resignation of Jayantha Katagoda, who was succeeded by Basil Rajapaksa, and the subsequent resignation of Ajith Nivard Cabral, leading to Katagoda's reappointment. A.H.M. Fowzie replaced Mujibar Rahman, while Rahman later returned to fill Diana Gamage's seat due to a court ruling. Notably, no replacement was made for Harin Fernando’s vacant seat.

The major highlight of this parliamentary term was the election of Ranil Wickramasinghe as the 8th Executive President, following the resignation of Gotabaya Rajapaksa. This event necessitated the appointment of a new MP to take Ranil Wickramasinghe’s former seat.

The Ninth Parliament experienced four prorogations, initiated by both former Presidents Gotabaya Rajapaksa and Ranil Wickremesinghe. The five sessions ran as follows: the first from August 20, 2020, to December 12, 2021; the second from January 18, 2022, to July 28, 2022; the third from August 3, 2022, to January 27, 2023; the fourth from February 8, 2023, to January 26, 2024; and the fifth from February 7, 2024, until dissolution.