- Aeronautical Society
- Art Club
- Association of Innovation and Design
- Association of Science and Technology
- Automobile Club
- Buddhist Students’ Association
- Canto Perpetua Choir
- Carnatic Orchestra
- Classical Music Association
- Commerce Society
- Cubing Society
- Culinary Arts Society
- English Drama Society
- English Lit & Debating Society
- Gavel Club
- Geography Society
- Health Club
- Hewisi Band
- Hindu Students’ Union
- Histoarcheo Club
- HNB Students’ Savings Unit
- ICT Society
- Interact Club
- Islamic Society
- Junior English Lit & Debating Society
- Junior Maths Society
- Junior Science & Technology
- Kennel Club
- Media Unit
- Photographic Club
- Political Science Society
- Productive Citizenship Society
- Quiz Club
- Scuba Diving Unit
- Radio Club
- Red Cross Society
- Road Safety Patrol
- Senior Environmental Club
- Seylan Bank Students’ Savings Unit
- Sinhala Literary & Debating Society
- Society for Social Work & Welfare
- Spelling Union
- Student Christian Movement
- Tamil Drama Society
- Tamil Literary and Debating Society
- The Ternion
- Thomian Union
- United Nations Club
- Western Band
- Wildlife Society
Scuba Diving Unit
The S. Thomas’ College Sub-Aqua Club (STCSAC) was the brainchild of two old boy diving enthusiasts of the school. We are now the old boy support group to the S. Thomas' College Scuba Diving Unit (STCSDU), an extra curricular activity classified as a sport since February 2015. Our training programme introduced at inception has evolved over the years and is best judged by the quality of divers we continue to produce to date. We look forward to seeing you and hope you’ll join the club! https://www.stcsac.lk/the-club/join-usLatest Project
Jan to Apr - AGM (Jan) - Exhibition Dive at the OBA lunch (Feb) - Participation at Rendezvous (Feb) - Reef/wreck Clean-up (Feb/Mar) - Low visibility dive expedition (Feb/Mar) - Dive trip Hikkaduwa/Kalpitiya (Mar/Apr) - First Aid Programme (Mar) May to Sep - Monsoon Fin - STCSAC vs STCSDU Underwater Hockey Tournament - STCSAC vs SLSAC Underwater Hockey Tournament - Dive trip East coast - Record breaking challenge Oct to Dec - Beach Clean-up (Oct) - Exhibition Dive at the Lower School Swimming Gala (Oct) - Dive trip down south (Dec) - Christmas party