The Montreal Fire Club was formed by a group of prominent merchants and businessmen for the mutual protection of its members from fire. Isaac Todd, Thomas McCord, James McGill and Benjamin and Joseph Frobisher were among the founding members of the club. The club held its first meeting in April 1763. The members of the club were provided with firefighting equipment and were expected to familiarize themselves with the other members houses and warehouses to provide assistance if needed.

The Montreal Elgar Choir was incorporated in 1924 through the amalgamation of the Elgar Women's Choir (founded in 1921) and the Apollo Glee Club, directed by Berkeley E. Chadwick. Chadwick, organist at the Erskine-American Church and music teacher at a number of private schools, became the new choir's first director. He was succeeded in 1951 by Gifford Mitchell, lecturer (1957, 1963-1965) and Assistant Professor (1966-1969) of music at McGill and music supervisor for the Protestant School Board of Greater Montreal. Since 1969, the choir has been directed by Graham Knott (1969-1972) and Brock McElheran (1972-). Maureen Forrester made her professional debut in 1951 with the Choir, performing Elgar's "The Music Makers".

The Montreal Council of Social Agencies, a coordinating organization for English-speaking, non-Roman Catholic social agencies, was formed in 1921 by John Howard Toynbee Falk, head of McGill's Department of Social Studies, later the McGill University School of Social Workers. Although details of the organization of the MCSA have been modified over the years, the basic structure remained constant: a Board of Directors, elected from the member agencies, directed the MCSA through administrative standing committees and, more importantly, set up numerous special committees to study specific social problems under the aegis of area advisory groups for health, aging, urban renewal, recreation, etc. The overwhelming emphasis of the MCSA on planning and research reflects its role as animator, information exchange and coordinator of a great variety of social agencies and groups, from major hospitals and fund-raising organizations to church groups and boys' clubs. In 1968, the MCSA merged with its French homologue, the Conseil de Développement Social; it ceased operations in 1976.

The first meeting of the Montreal Cardiac Society was held on the 30th of October, 1946 in the Physiology Library of McGill University. It followed a preliminary meeting to discuss the need for such an organization in Canada, held on the 25th of September, 1946 chaired by Dr. H.E. Hoff and attended by Drs. H.N. Segall, H.E. Shister, Lyon J. Korenberg, Pierre Marion, G.R.Brow, S. Eidlow, R. Lefebvre, George Garneau, A.L. Johnson, J.H. Palmer, W.H. Philip Hill, C.C. Birchard, C.F. Moffatt, C.R. Bourne, W.W. Eakin.

In 1822 a group of Montréal businessmen, perturbed by the effects of the depression which followed the end of the Napoleonic wars, formed a "committee of Trade" with a mandate "to watch over the general interests of the trade of the country". The Committee was incorporated as the Montreal Board of Trade in 1842. During its first century, the Board's role was primarily that of lobbyist, particularly with regard to improving navigation to Montréal and constructing port facilities. They have been closely involved in municipal administrative reform, public health campaigns, anti-pollution and slum-clearance drives. Since the 1920s, the character of the Board has gradually altered to that of an information clearing-house and education facility.

The Montreal Anti-Tuberculosis and General Health League was organized in 1924 to coordinate research into public health conditions in the city, to stimulate public interest in and knowledge of these problems, and to lobby for government action. The League sponsored publications, conducted popular courses, funded the hiring of public health nurses, and made surveys. They operated out of both English and French headquarters. With the establishment of the Board of Health, the League considered its main purposes achieved and disbanded in 1930. Many prominent Montrealers sat on its board of directors, under the chairmanship of Sir Arthur Currie.