. The school was founded by the Rev. Joseph Marsh, the acting Colonial Chaplain at St. Paul's Church as the Hill Street Academy in 1835, as a private institution with 20 students, mainly from the upper class community situated at Hill Street, Pettah. In 1836, Sir Robert Wilmot-Horton, the British Governor of Ceylon, based on the recommendations of the Colebrooke Commission converted it, as the Colombo Academy[4], into an English public school modeled on Eton College, with Marsh continuing as Head master. The oldest public school on the island with the governor as its patron, it gavee to the children of leading Ceylonese an education which would make them fit to be citizens of the British Empire and serve as the principal public school and a model for other government schools that were to be built in Ceylon.[5] In 1836 the school was moved to San Sebastian Hill, Pettah, (prior to which it was at Maradana, next to Hulftsdorp) it would stay there for another 75 years before being shifted to Thurstan Road

The college today
Since its establishment the main medium of education had been English, however with Sinhala becoming the official language along with Tamil the medium of education was changed to Sinhala and Tamil. Since 2002 English as been reintroduced as a medium of education at the College. Students may select one of the three mediums in which to conduct their studies.
The school is equipped with facilities such as lecture halls, science and computer laboratories, auditoriums etc. This includes the 'College Hall' and the Navarangahala which is a national theater.
The first hostel of the Colombo Academy was established in San Sebastian in 1868, establishing Royal as one of the first boarding schools in Sri Lanka. Since then the school has maintained a hostel for students from outside Colombo, with around 230 hostelers.
Sport plays a major part in Royal College's activities. The school's facilities include a swimming pool, cricket and athletics grounds, tennis courts, indoor cricket nets and an international standard sports complex. The sports complex, built in 2000, a short distance from the college, hosts national and school sporting events year round