The Ontario Science Centre opened to the public on September 28, 1969, in a building designed by Toronto architect Raymond Moriyama, and the province closed that Don Mills Road building on June 21, 2024. The science centre itself continues in temporary form at Harbourfront Centre, and a new building is under construction at Ontario Place with an opening planned for 2029. The original site is not open to visitors.
Opening in 1969
According to Wikipedia’s article on the centre, construction began in 1966, an official opening took place on September 27, 1969, and the public was admitted the following day. Its infobox gives September 26, 1969, as the establishment date, so sources vary by a day or two. Raymond Moriyama designed the building, which was set into the Don Valley slope on Don Mills Road.
The closure of June 2024
On June 21, 2024, the Ontario Ministry of Infrastructure announced the immediate closure of the Don Mills building. The stated reason was an engineering report that found water damage affecting 2 to 6 percent of the roofs and raised concerns about the building’s reinforced autoclaved aerated concrete roof panels. The report estimated repairs at $22 million or more and about two years of work, according to Wikipedia, which cites CBC News and the Toronto Star of that date. Critics have disputed whether closure was necessary, and that question remains contested.
What came after
Most exhibits went into storage, and animals and plants were moved to the Toronto Zoo and The Village at Black Creek, according to the same article. Pop-up exhibits opened at Sherway Gardens and at Harbourfront Centre. When this page was read on October 27, 2026, the centre’s own website listed the Science Centre as open at Harbourfront Centre, 235 Queens Quay West, with a notice that part of the space would reopen in late November after maintenance by Harbourfront Centre. The site’s pages show no publication date, so the Harbourfront operator’s page should be checked before any trip, along with the hours it lists.
| Date | Event |
|---|---|
| September 28, 1969 | Centre opens to the public |
| April 18, 2023 | Premier Doug Ford announces the move to Ontario Place |
| June 21, 2024 | Don Mills building closed by the province |
| May 25, 2026 | Reported start of construction at Ontario Place (CTV News) |
| 2029 | Planned opening of the new building |
The planned move to Ontario Place
Ford announced on April 18, 2023, that the centre would move to a smaller facility at Ontario Place on the waterfront. CTV News reported on May 25, 2026, that construction of the new Ontario Science Centre had begun, and news coverage describes a planned opening as early as 2029. The Ontario Auditor General found in December 2024 that relocation costs had already exceeded projected savings, according to Wikipedia. Cost estimates in the press range from about $1 billion to about $1.4 billion and are not settled. The Ontario Place site has its own article here.
Why hands-on exhibits matter
Science museums generally teach by letting visitors act, and the idea applies to any subject: learning about human anatomy is not limited to passively observing displays when models, measurement, and demonstration are part of the visit. Whether the future centre follows this approach is a matter for its operator to state, and none of the sources read here describes the exhibit plan in detail.
Frequently asked questions
Is the Ontario Science Centre open?
The Don Mills building has been closed since June 21, 2024. The centre’s website, read on October 27, 2026, lists a temporary Science Centre as open at Harbourfront Centre.
Who designed the original building?
Raymond Moriyama.
When will the new building open?
The province has said 2029, “as early as” in earlier announcements, so the date may change.
Why was the Don Mills building closed?
The province cited an engineering report on roof panels, while critics dispute the need to close it.
Last verified: October 2026
Sources
- Ontario Science Centre, official website, read October 27, 2026
- Wikipedia, Ontario Science Centre, which cites CBC News and the Toronto Star, June 21, 2024
- CTV News, Construction of new Ontario Science Centre begins, May 25, 2026 (headline and date only)
Related reading
- Ontario Place: history of the waterfront site
- The Royal Ontario Museum
- Don Valley Brick Works
- Toronto City Hall, 1965
- Visiting Toronto: the hub
Cite this page
APA: History of Toronto. (2026, October 27). Ontario Science Centre: 1969 Opening, Closure, Ontario Place. http://localhost:8210/blog/explore-the-wonders-of-science-at-science-centre-toronto
MLA: “Ontario Science Centre: 1969 Opening, Closure, Ontario Place.” History of Toronto, 27 Oct. 2026, http://localhost:8210/blog/explore-the-wonders-of-science-at-science-centre-toronto. Accessed .
Chicago: History of Toronto. “Ontario Science Centre: 1969 Opening, Closure, Ontario Place.” Last modified October 27, 2026. http://localhost:8210/blog/explore-the-wonders-of-science-at-science-centre-toronto.
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