Central School for Tibetans, Shimla formerly known Tibetan Refugee School Shimla, came into being in early 1961 under the Principal of Shri Sonam Topjor Tethong. The strength of Mussoorie and Dharamsala School exceeded their intake capacity and hence the need for another school for Tibetan refugee children was urgently felt. When the officials deputed from Dharamsala came to Shimla in search of a good campus for school, they saw a huge colonial building called "Torrentiym Cottage" with a small class room block and a playground which then used to house the junior section of Bishop Cotton School. After negotiations, and agreement was signed on December 1, 1960 between the Representative of H. H. the Dalai Lama and the Governing Body of Bishop Cotton School by which the whole property was to be initially rented and ultimately purchased.

Shri Sonam Topjor Tethong, the first Principal and his assistants had made the necessary arrangements when the first batch of 160 students arrived from Dharamsala Nursery. Later on, from time to time more students joined the school.

The school was taken over by CTSA, which as erstwhile called Tibetan Schools' Society (TSS). In the later part of 1964, the school campus was further extended with the purchase of the adjoining building, out-houses and a Tennis Court known as "Villa Torrents". It was done during the tenure of Pt. Shyam Narayan, the first Secretary of CTSA.

The school progressed day by day. With the arrival of more and more children the existing accommodation was proving to be inadequate. So, at one time, a branch school was opened at Earlsfield near St. Beades' College.

In 1973, the first batch of Higher Secondary School (Class XI) was groomed to appear in the All India Board Examination from this school and the batch fared quite well and paved the way for the next batch. But when the second batch was all set to sit for the examination they were sent to Mussoorie to augment the strength of that school.

In 1975, the second and the last group of Higher Secondary students in the old pattern of education took their board examination from this school. It was the year when the new education system of 10+2+3 was introduced as a result of which three out of four residential schools were turned into Senior Secondary (+2) schools. CST Shimla, however, remained Secondary schools (Class X) due to lack of infrastructure facilities.

On October 27, 1983, the main Torrentium building which housed the girls' hostel and junior boys' hostel was gutted in a fire accident due to electric short circuit. Fortunately, no loss of life occurred in the accident although it was a major fire during odd hours. Since then, a hostel building with an intake capacity of 350 children, a class room block and a Library block have been constructed during the tenure of Shri. S.P. Datta, the incumbent Secretary of CTSA.

The school was upgraded to Senior Secondary level in the year 1987. As of now, the school has around 500 students out of whom 312 are boarders and the rest are day-scholars. It has become one of the premier learning institutions for Tibetan refugee children. The product of this school has now assumed prestigious post in the Tibetan Exile Government hierarchy.