- 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
Hewisi Band
The Hewisi Band of S. Thomas' College Mount Lavinia is one of the main activities in College. It has a proud reputation and fascinating history throughout the previous years. The objective of the College Hewisi Band is to uplift the standards of Sri Lankan traditional, oriental and contemporary music to the optimum level to give a taste of our culture to the younger generations. We as a band try to derive the hidden talents of our College students and to give out a fabulous output.Latest Project
Kailasa '19
The main event of the Hewisi Band is hosting its annual Hewisi Band concert along with the participation from invited schools. We always continue the traditions which were passed down from the previous Hewisi Bandsmen.

