When the Maryknoll Sisters arrived in Hong Kong in 1921, people wanted a school and the Sisters responded to their wishes. Maryknoll Convent School began as a kindergarten with 12 toddler students at the Sisters' parlor at 103 Austin Road on 11th February, 1925.

As enrolment increased, a proper school building was needed. The cornerstone of the beautiful campus of Maryknoll Convent School, located at the corner of Waterloo Road and Boundary Street, was laid and completed its construction in 1937. It received territory-wide compliments for its architecture and became a grant-in-aid institution opened to 400 young ladies in September, 1937. 

During the war, Maryknoll Convent School was occupied and used as a military hospital. At the time, there were 651 students in 16 classes and 21 teaching staff (including 12 Sisters) when the school was suspended.

With the generous donations and joint effort from different parties, the school was reopened on 8th January, 1946. It took three years to repair and refurbish the school fully.

The school continued to grow and develop rapidly and became a model of quality, holistic and Christian education. With a new science laboratory repleted with the latest equipment, Maryknollers’ interest in science grew. 

The secondary section moved to its own building on 5 Ho Tung Road, adjacent to the primary section. This move allowed the Primary Section to add an extra stream from Primary 1 to 6, thereby substantially increasing the enrollment.

To ensure that MCS would remain at the cutting edge of quality education, the Maryknoll Convent School Educational Trust was set up by some devoted former students in 1992. Their aim was to raise the funds necessary to assist in the operation of the school, and help keep MCS in the vanguard of modern education.

The regional house of the Maryknoll Sisters was turned over to the Primary Section, enabling MCSPS to become a whole-day school. The members of the Trust secured the benefaction of the Hong Kong Jockey Club and generous donations from parents, alumnae and friends of Maryknoll Convent School, resulting in the addition of 15 classrooms, an Assembly Hall, a canteen and a number of special rooms to the Primary Section.

The Sisters decided to turn over the sponsorship of Maryknoll Convent School to its former students, who they believed can best transmit the Maryknoll spirit as they have experienced it, loved it, been loyal to it, and lived by it. The Maryknoll Convent School Foundation was then established by a group of devoted former students and assumed the sponsorship of Maryknoll Convent School on August 31, 2005.

The MCS school building at Waterloo Road and Boundary Street (including the convent building) was declared a monument under the Antiquities and Monuments Ordinance.

Maryknoll Convent School proudly celebrates its 100th anniversary, marking a century of educational excellence.