In 1956, a certification program for technicians and technologists was started by the Association of Professional Engineers of Ontario (APEO), now known as
Professional Engineers Ontario (PEO). The first certifications were granted on June 5, 1957. OACETT was incorporated in 1962 by the APEO. APEO reserved the
post-nominal "CET" under the federal Trademarks Act, and later transferred ownership to OACETT. OACETT played a role in the 1973 formation of the
Canadian Council of Technicians and Technologists (CCTT), a federal parent organization with which OACETT was affiliated. By 1977, OACETT's Bylaw 15 had adequately established its own registration board separate from the APEO, asserting its independence. In 1984, the Legislative Assembly of Ontario granted OACETT self-governing status, with Royal Assent of the OACETT Act, Statutes of Ontario. The act recognized OACETT as a professional body whose main objective is to establish and maintain high standards for the engineering and applied science technician and technologist professions. The Association's disciplinary and registration tribunals became formalized and subject to the Statutory Powers Procedure Act and Judicial Review Procedure Act, with their decisions appealable to the Divisional Court of the Superior Court of Ontario. These statutes reserved titles and their respective
post-nominals, making their use by non-members unlawful under the Provincial Offences Act and triable by the Ontario Court of Justice. In 1998, a revised version of the OACETT act was passed by the Ontario Legislature. In 2006, like other self-governing and self-regulating professional bodies in Ontario, OACETT's registration and admissions procedures became subject to the Fair Access to the Regulated Professions Act. In 2010, OACETT withdrew from CCTT and no longer has an affiliation. They are now affiliated with
Technology Professionals Canada, an organization they helped found. ==Certification==