On September 8, 1950 eleven people gathered at the home of Harry and Phoebe Billings to begin a new stamp club in London. Since the table they sat at was round they called their new group the Middlesex Stamp Circle. The other charter members were John Butt, Max Doupe (vice president) Frank Hopkins, Kathleen Jenkins, Larry Langford (president), Norm Perry, Harry and Mrs. Shaw and Tom Stewart (secretary-treasurer).
The first public meeting was held later that month on the Central Library on Queen's Avenue. The objective of the club was soon formulated to give direction to the new organization. This was: To promote amateur Philately by means of co-operative study, discussion and good fellowship among its members. Membership was $2 a year.
Guy Mills was the first member to join and was among the 15 members who exhibited at the first exhibition. Annual exhibitions have been held every year since. The first show was held in April of 1951 at the Central Library. Exhibits were mostly British Commonwealth with some U.S.; Mrs. Billings entered a topical exhibit 'Red Cross'. The club put in exhibits at the Western Fair that year. A member Ephraim Werner exhibited 'The History of Stamps in Canada from the first Postage Stamp to the Current Issue. Since this was the Centenary of the first stamps issued in the 'Province of Canada' in 1851 his exhibit drew much attention.
Social Activities have always been an important part of the club. In the early years picnics were held in Gibbons Park and club members have shared pot-luck, catered and restaurant meals since 1951.
Club meeting locations for the first 21 years were at the Central Library, then the Crouch Library with yearly exhibitions being held at these libraries. When the meetings moved to the Landon Library in 1972, the club held its first exhibition with a dealer bourse at the Dundas Street Centre United Church in November.
In the fall of 1984 the meetings moved to the Elmwood Avenue Presbyterian Church and the Middlesex Stamp Circle changed its name to the Middlesex Stamp Club. In January 1997 the meetings moved to St. Martin of Tours Church Hall and beginning in January 2016 meetings have been held at St. Michael and All Angels Church.
In 1987 it was decided, that in the interest of more widely promoting stamp collecting to move the exhibition to a more public venue. To this end White Oaks Mall was approached. An agreement was reached and shows were held there until 2006 when they were moved to Argyle Mall. Shows were then held at the Westview Baptist Church from 2012 to 2015. In 2016 CANPEX started, sponsored by the Middlesex Stamp Club. Shows are held at the Hellenic Community Centre on Southdale Road. In 2017 CANPEX became a national level show with the show's Grand Award winner moving on to exhibit in the American Philatelic Societies 'Champion of Champions' exhibit.