St. Theresa’s High School grew out of St. Andrew’s Indian Christian School, housed in a very dilapidated building situated in Old Khar. This school was founded in 1918 and taken over by our religious society called Society of the Divine Word (S.V.D.) in 1952. Fr. Peter Braun stepped into the shoes of Fr. Proksch in February, 1951. He set before himself the idea and ideal of building first a school. His Eminence, Valerian Cardinal Gracias laid the foundation stone of the new school on the feast of St. Theresa on 3rd October, 1952, in the centre of an entirely new residential area in Bandra. In addition to the 6 plots bought by Fr. Gomes, Fr. Braun acquired 6 more plots for the church and the school between November 29, 1951 and November 15, 1957, the total area being 4985 sq. yards for Rs 56,710. October 1955 saw the parish in a gala affair when her newly- consecrated son, the Most Rev. Dr. Longinus Pereira, the Auxiliary Bishop of Bombay, blessed the school and celebrated Pontifical High Mass on the terrace. From that day the original name was changed into St. Theresa’s School.
In the year 1955 under the able guidance of Fr. Partsch, SVD as its first Principal, the school stated with 118 pupils on roll. S. Theresa’s became a full fledged High School in 1961 when the first batch of students were sent up for SSC examinations. Recognition as a full-fledged High School was accorded in 1960, (vide BCD 43 dated 27-6-1960 EI-GB). By 1963, all girls sections except Std X and XI went over to Duruelo Convent. In 1968 under the guidance of Fr. Jungblutt, the then principal, a new extension to the school was added, which provided more classrooms and a half for the parish.
When Fr. J. Partsch (1951 – 1956) left, Fr. A. Malina took over the stewardship in 1956 and he was succeeded by Sr. Cecelia for a year (1960 – 1961); Fr. L. Jungblut was in the rein from 1962 – 1971; Fr. Clement Godwin who was a popular assistant in the parish and teacher in the school for several years also acted as Principal when Fr.L. Jungblut went to Europe on home leave. Fr. K. Pottanani who was already in the staff of the school for a few years, succeeded Fr. Jungblut in 1971: Fr. J. Nallor succeeded Fr. Pottanani in 1977 until his retirement in 1990. Fr. Jerome D’Souza follwed Fr.Nallor till 1998.
Fr. Anthony Joseph was the Principal from 1998 till 2009 after which Fr. John Mascarenhas took over. Other SVD members who served the school are Frs. Varghese Chalamana and Venance Ashirvadam: both now serving in Andhra missions.
Fr. Leo made an extension in the form of the north and south wings of the school and constructed the second floor.