St. Mary’s is one of the most prestigious schools of Kolkata (erstwhile Calcutta) and has one of the most spacious campuses in the city comprising two football fields, an auditorium, a basketball court, a skating rink, parks, badminton court and class rooms. The school also has a library, computer centres, laboratories and a chapel hosting mass and other holy events.
As the school was also a residential school for orphans and the underprivileged till 2006, it also has dormitories, a dining hall and a kitchen, along with servants’ quarters and the three main school buildings. However, the boarding closed down in 2004 and the school is now run as a day school only.
St. Mary’s provides education under the ICSE/ISC board, New Delhi and is run by the Congregation of Christian Brothers of Ireland. SMO has classes from the Kindergarten section up to +2 level i.e. Class XI and XII (Commerce section only). From the 2012 session admission of girls to the +2 level has started, breaking the school’s long-standing reputation of being a premier boys’ only school in Calcutta.