S. Thomas' College, Mount Lavinia (abbreviated as STC), is a fee-levying Anglican selective entry boys' private school in Sri Lanka.

The college has educated prime ministers, world leaders, sportsmen and Booker Prize winners.

Many of the prominent leaders of Sri Lanka's independence movement in the early twentieth century were educated at the college.

S. Thomas’ College is situated in a quiet suburb approximately half an hour from the southern limits of the City of Colombo.

[5] The school's administration remains deeply rooted in Anglicanism, with a further chaplaincy for the aforementioned Chapel of the Transfiguration.

These combined sectors amount to the college's student body of approximately 2,800 – stemming from varied faiths and ethnicities.

[7] Chapman's vision included building as a college and cathedral for the new Diocese of Colombo of the Church of Ceylon, modelled on the British Public School system he was accustomed to.

In 1918, the school moved away from the "dusty environs" of Mutwal, which was near the Colombo harbour, to a more picturesque location near the sea in Mount Lavinia.

[17] In 1968, David Paynter, the noted Sri Lankan painter, completed his mural of the Transfiguration of Jesus upon the interior of the east wall of the chapel, which included a then unusual "beardless Christ".

[19] The lyrics of the College Song were written by Mr. Edmund de Livera, a Royalist; and music was composed by Revd.

The 5th line of the 2nd verse was amended in the time of Warden M. L. C. Illangakoon on a suggestion made by the late Mr. Mervyn Casie-Chetty, and ‘King’ was replaced by ‘State’.

There was also a small, rather short-lived Winchester House (although the present Primary School boarding facility is still known by this name).

[21] An organised house system was introduced following the school's founding by Warden K. C. McPherson, with the aims to encourage boys to take part in extracurricular activities.

These sports take precedence because of the importance given to the clash between S. Thomas' oldest rival, the Royal College, Colombo.

As the year ends with the term of Yuletide, the highlights are the Royal Thomian Regatta and the Boat Race for the oarsmen of the two Colleges and simultaneously the two leg Water Polo matches for the R.L.

It is the second longest uninterrupted cricket match series in the world and the first and oldest in Sri Lanka, even older than the Ashes, having been played for more than 140 years continuously.

[27] The original match was played between the Colombo Academy and S. Thomas' College, Mutwal,[28][29][30][31][32][33][34][35][36][37][38] in 1879, with schoolmasters participating as well as schoolboys.

However, while it is still a two leg event, for the past several years it has been held at the Sugathadasa Stadium Swimming Pool allowing for much larger participation and making it the best patronised Water Polo matches in Sri Lanka and Asia.