- Bishop Ferguson-Davie, the first Bishop of the Anglican Diocese of Singapore proposed the setting up of an English High School for girls. Miss Eveleigh was appointed the first Principal.
- On 4 November, the school was opened in a house, 18 Weld Road, with Miss Eveleigh, Miss Chitty, who was in charge of women's work, and 3 students.
- The school moved to Ampang Road.
- Miss Eveleigh went on leave and was succeeded by Miss Playne.
- Miss F.C. Pope arrived and took charge of music.
- In January, the school was reorganized as St. Mary Girls School and St. Mary Church took responsibility for it.
- Miss Playne resigned and Miss Pope became Principal.
- The school was now in two semi-detached houses off Lake View Road. There were 22 students and 8 boarders.
- The Weld Hill Road property was bought this year for the sum of 36,000 pounds under the name of the Bishop of Singapore and Malaya. It was a 9-acre site.
- In September, the school moved to 7 Treacher Road, into the building which is now a bungalow. There were now 54 students and 4 boarders. The staff consisted of Miss Pope, Miss Kay, Mrs. King and Miss Alice Chen.
- Later in the year, Miss Pope resigned as Principal.
- In June, Miss McNeil arrived as Principal.
- At the end of the year, Miss Pope gave up her work in St. Mary's and returned to England.
- The Reverend A.B. Champion opened the Boy's Department and Boarding House.
- In November, construction began on the Weld Hill Road property and was completed the following year.
- The St. Mary's Association was formed.
- An extension was added.
- Miss Majorie Pring joined the staff.
- Miss McNeil retired and Miss Pring became the Principal.
- Science and Biology were introduced into the School Certificate Examination.
- Miss Sprenger became the Acting Principal during Miss Pring's furlough.
- The school badge was introduced and the symbols are as follows:
- The Lily of St. Mary
- The Motto 'I SERVE'
- The Lamp of Learning
- The school uniform was adopted.
- The first issue of the school magazine was published.
- The Girl Guide Movement was introduced with the formation in August of the Second Guide Company (K.L) with 27 recruits.
- In March, the Boys' Department had to be closed, as there were insufficient boys to form a class.
- In October, Miss Florence Carpenter, an Arts graduate from Reading University and a S.P.G. missionary arrived to teach Scripture, English and History in the upper class.
- The school enrolment stood at 318 students in the primary and secondary streams and 62 students in two kindergarten classes.
- The Sports House systems was introduced ant the original names were those of the Federated Malay States.
- Negeri Sembilan-Blue
- Pahang House-Green
- Selangor House-Red
- Perak House-Purple
- 2 June, Miss Pring left for England on furlough and Miss Carpenter became the Acting Principal.
- With the outbreak of war in the Far East, schools in Malaya were closed. Miss Carpenter went to Singapore and later in a year was evacuated to India.
- The School building was used as a military hospital by the Japanese.
- 28 June, Miss Pring was killed in a fall in Kashmir.
- 18 October, the school was reopened with Miss Edna Yzeldman as the Acting Principal.
- The kindergarten was opened with Miss Frnak in charge.
- 12 February, Miss Carpenter returned to Malaya and was appointed Principal of St. Mary's.
- 6 April, the Governor of Malaya, Sir Edward Gent, visited St. Mary's.
- The School Certificate class was combined with that at Pudu English School because of shortage of staff.
- Full classes resumed when school reopened on 20 January and great progress was made under Acting Principal, Mrs. Agnes Pinnick.
- The first drama "The Siege of Ping" and "Alice in Wonderland" was presented to the public on 8 and 9 August.
- Temporary classroom near the road were built to accommodate the increasing enrolment.
- The names of the Sports Houses were changed to that of past Principals.
- The school enrolment reached 500.
- The School Certificate class obtained 100% pass with 10 out of 23 Grade Ones.
- The Domestic Science Room, now at present library was constructed. Home Science was introduced to the students in Form 1 and 2.
- 14 October, the School Birthday was celebrated for the first time.
- 10 July, the Parents-Teachers Association was formed.
- 1 November, the new classrooms in the primary school were opened by Bishop Roland Koh.
- 1 January, the primary and secondary schools were separated. Mrs. Louise LaBrooy became the Headmistress of the Primary School.
- 15 October, the new block comprising the science labs and the canteen was opened by Bishop Roland Koh.
- Mrs. Fowler succeeded Mrs. LaBrooy as Headmistress of the Primary School.
- 4 January, students in Form 4 were introduced to Arts and Science Streams.
- The Golden Jubilee Year of St. Mary's was celebrated. A special Jubilee edition of the school magazine was produced.
- Celebrations began on 18 October.
- Miss Carpenter retired as Principal of the school.
- Miss Diane Sellors became Principal of the school.
- The new extension comprising of the Art room, Domestic Science rooms and classrooms was opened by the Minister of Education Encik Mohd Khir Johari on 4 February.
- 13 May, the school was closed because of the nationwide riots and reopened on 2 June.
- 1 August, Miss Sellors went on leave prior to her retirement and on 14 August Mrs. Maureen Morel became the first Asian Principal to be appointed to the post.
- Mr. Rajendran took over as Principal.
- Leadership Training Course and Prefects Installation were introduced to the students.
- In February, Religious Emphasis Week was introduced and in May Library Week.
- In October, a full-length musical drama 'Joseph and His Technicolour Dreamcoat' was put up for the public in conjunction with the Speech Day.
- The School Band was formed.
- The Musical Drama 'The Boyfriend' was staged for the public.
- Ms. Richards took over as Principal of St. Mary's.
- The full-length musical 'Snow White and the Seven Dwarfs' was staged.
- Extensive renovations were carried out and the school was given a new coat of paint.
- The school celebrated its 75 th Anniversary.
- The musical 'The Sound of Music' first staged in 1979 was staged again in the school hall to the public.
- The school celebrated her 80 th birthday.
- Dato' Stanley Isaacs became Chairman of The Board of Governors.
- The new block of two classrooms and two specialist rooms was opened.
- The last musical 'Annie Get Your Gun' was produced in the premises in Jalan Tengah. The Patron for the show was Dato' Endon Mohammed, past pupil of the school.
- The school land in Jalan Tengah was sold to the Lion Group and negotiations began with the Ministry of Education regarding the school.
- 10 May, the model of the new school was displayed to the public at Speech Day. The guest of honour was Datin Seri Dr. Siti Hasmah, past pupil of the school from 1934 to 1941.
- In December, (the big shift began to the new school) situated on a 9-acre site at Taman Intan Baiduri, Selayang. The estimated cost of the building is RM 33 million.
- On the 5 th January, school term started off with the enrolment of 410 students in 10 classrooms at the new premises.
- 21 Feruary, the St. Mary's School Association held a "Reunion Dinner" at the school premises in Jalan Tengah with a total of more than 800 ex-students.
- 31 March, the Anglican Diocese of West Malaysia handed the keys of the old school to the Lion Group.
- By the end of the year, all Science Laboratories, the VIP room and meeting room were fully equipped.
- On 6 March, the first fund-raising campaign was held in the new premises netting RM 50,000.
- 15 July, the PA system for the whole school was set up from the fund from the Pesta Ria.
- 4 September, the row of tembusu trees was planted as a reminder of the old school.
- March, the hall was equipped with motorized stage curtains and a wood paneling façade, through the generosity of the St. Mary's Association.
- On July, the new school building in Taman Intan Baiduri was officially opened by Y.A. Bhg. Dato' Seri Dr. Siti Hasmah bt. Haji Mohd. Ali, former pupil and wife of the Prime Minister. Also present was Dato' Endon Mohammed, former pupil and wife of deputy Prime Minister. The same day also saw the launching of the school's website: http://www.smkstmary.homepage.com
- On 24 February, the second fund raising campaign was closed with a jogathon.
- 15 June, saw thee official opening of the Computer Laboratory by Datin Amar Elizabeth Moggie, wife of the Minister of Telecommunications, Multimedia and Post.
- 6 July, farewell celebrations were held for Ms E. N. Richards by the school, Parents-Teachers Association and Board of Governors. On the same day, a farewell dinner was organized by the St. Mary's Association, held at the Grand Seasons Hotel.