The Buddhist Society of S. Thomas’ Preparatory School was founded in the 1980’s. In 1982, the students organised a Sil Campaign at the Dharmakirti Aramaya, Polwatte for the first time. This tradition has sustained throughout the years. Additionally, the society also makes a donation to the needy every year, using the collection money that is obtained weekly from the students.
The Buddhist Society committee consists of a President, Vice President, Secretary, Treasurer and Editor, who are all from Grade 11. Furthermore, all the Buddhist students from the Middle and Upper School are members of the society.
Initially the staff advisor of the society was Mrs. S. Sureshchandra. Subsequently, Mr. Kumara Silva took over and the society was managed by Mrs. Nimali Gamage during his absence.