The Ontario Science Centre is one of the first interactive science museums in the world. 

The first plans for the museum were made in 1961, and three years later the Canadian-Japanese architect Raymond Moriyama was commissioned to draw up designs for the new building on a parkland of over 40 hectares. Moriyama envisaged three main buildings, which were to be connected by bridges and escalators. Care was taken to arrange the buildings of the complex in that way that removal or damage of the mature trees could be avoided. Construction work began in 1966 and the museum opened to the public on September 27, 1969. 

The buildings exhibit brutalist qualities, for example through various textures of raw concrete walls with even, wood imprinted, and bush-hammered exposed concrete sufraces on the in- and outside, as well as by the various sculptural parts of the buildings, executed in monumental dimensions with partly round, partly straight or sloping structural forms and elements.

Over the years, the museum has undergone various extensions and renovations. In 1996, an IMAX dome was opened. Due to structural decay, a pedestrian bridge was closed by 2023.

Currently, the Ontario Science Centre is in danger. It was permanently closed to the public on June 21, 2024. The closure is related to a technical report published on the same day, which found that 2–6% of the roofs were at high risk of collapse under snow load in winter and recommended repairs—but by no means the closure of the building. So instead of repairing it, the government used the technical report as an opportunity to refer to plans announced in 2023 to replace the Ontario Science Centre with a smaller institution on the Toronto waterfront on the Ontario Place site, which is scheduled to open in 2028. The relocation plan and the resulting threat of demolition for the Ontario Science Centre building has triggered widespread backlash from many community and professional groups (last updated on July 2, 2024).