- Philatelic & Numismatic Society
- Robotics Club
- Yoga Club
- Library Club
- Environmental Club
- College Magazine
- Chamber Orchestra
- Cinema Society
- Astronomy Club
- Aquarium Club
- Scuba Diving Unit
- Culinary Arts Society
- Aeronautical Societya
- Junior Science & Technology
- Histoarcheo Club
- Geography Society
- Gavel Club
- Student Christian Movement
- English Lit & Debating Society
- Radio Club
- Junior Maths Society
- Road Safety Patrol
- Sinhala Literary & Debating Society
- Seylan Bank Students’ Savings Unit
- HNB Students’ Savings Unit
- Kennel Club
- Buddhist Students’ Association
- Junior English Lit & Debating Society
- Art Club
- Spelling Union
- Carnatic Orchestra
- Canto Perpetua Choir
- Western Band
- Tamil Drama Society
- Hewisi Band
- English Drama Society
- Photographic Club
- Society for Social Work & Welfare
- ICT Society
- Senior Environmental Club
- Hindu Students’ Union
- Political Science Society
- Red Cross Society
- Association of Innovation and Design
- Islamic Society
- Association of Science and Technology
- Quiz Club
- Automobile Club
- Cubing Society
- Health Club
- Tamil Literary and Debating Society
- Wildlife Society
- Thomian Union
- Commerce Society
- Interact Club
- The Ternion
- Classical Music Association
- Media Unit
- Productive Citizenship Society
- United Nations Club
Radio Club
The Radio Club has been one of the most active clubs in the school since 1926 also making it one of the oldest clubs. The main function of the club is to teach its members the art of sound engineering and to use these skills in providing sounds for daily college activities from daily religious observances to main sports and other events.Latest Project
Virtual Radio Webinar 21'
Radio Webinar 21' is a virtual workshop held via online platforms organized by the Radio Club of S.Thomas' College Mount Lavinia to teach and educate the members and other individuals who are interested in learning the art of sound engineering.