Swimming is one of the successful sports currently practiced by Rahula College with All Island victories.
- 3rd place on the team rankings of national schools swimming, southern province in 2017
- 3rd place in Southern Province inter-school swimming championship 2017
- Under 13 Champions of RMP Memorial Swimming Championship which was organized by Dharmashoka College, Ambalangoda in 2019
- 2nd place on All Island Swimming Under 12 50m free style in 2018 – Anush Dissanayake
- 3rd place on All Island Swimming Under 12 50m butterfly style in 2018 – Anush Dissanayake
- 3rd place in Sri Lanka Schools’ swimming meet Under 18 50m breaststroke style in 2022 – K.H. Kulith Sathnindu