The venue is located on three artificial landscaped islands just off-shore in Lake Ontario, south of Exhibition Place, and southwest of Downtown Toronto.

The Government of Ontario has made controversial plan to place the 145 acres on a 95-year lease with the Swiss mega-spa builderTherme Group without public consultation or environmental assessments.

In the 1990s, despite the vocal protests of Eb Zeidler, the architect of the park among others, the Forum was torn down and replaced by the (misleadingly named) Amphitheatre, in truth a static proscenium arch stage with banked ticketed seating.

The government at first considered moving the Ontario Pavilion to a site on Toronto Island but instead decided at the instigation of Jim Ramsay, to build a facility elsewhere on the waterfront.

[2] We shall utilize the natural setting of the waterfront, modern structural designs, and hope to create the mood of gaiety and openness which helped make so popular the Ontario Pavilion at Expo '67 The park itself was originally conceived as an onshore exhibit, but this idea was discarded in favour of five large, architecturally unique, three-level pods in an aquatic setting somewhat similar in concept to Montreal's Expo 67 grounds (which were in the middle of the Saint Lawrence River).

Each pod would be approximately 8,000 square feet (740 m2) in area, and suspended by steel cables from four large central pylons driven deep into the lake bed.

Plans for the facility grew to include the Forum outdoor amphitheater, marina, nine restaurants, nine snack bars, three land rides, pedal and tour boats and an additional 33 acres (13 ha) of landfill.

Zeidler developed an innovative solution: after a trip to the Caribbean, he realized that a "barrier reef" concept would cut down on wave action from the lake enough to reduce the cost of the pods' foundation to 1/10 of the original open-water estimate.

To the south, a cost-effective and theme-congruent plan to sink three large obsolete Great Lakes shipping vessels was implemented, which sheltered the artificial harbour from intense open-lake waves.

Supporters of the plan believed that the dock's integration into Ontario Place would tie the location closer to the lake via boating activity, and improve the general ambience.

The design of Ontario Place has won a long list of awards including ones from the International Committee for Documentation and Conservation of Buildings of the Modern Movement, the Royal Architectural Institute of Canada, The National Trust — Prix du XXe Siècle, and the American Society of Landscape Architects.

[4] The first-year admission price: $1.00 for adults, $0.50 for students, $0.25 for children 6–12[12] To commemorate the opening of the theme park and promote the province of Ontario, a multi-media exhibition was created and presented inside the pavilion.

Redevelopment occurred on all three islands of the park; the pod buildings themselves were eventually closed to exhibit space and rented out as the "Atlantis" private event facility.

[19] A large reflecting pool nearby was drained and used to house the addition of a major "climber" structure, a smaller stage for kids shows and several other kid-oriented attractions, reducing the complete separation of areas that had been featured in the original design.

The outdoor in-the-round concert stage, The Forum, was torn down and replaced with the CA$15 million Molson Amphitheatre in 1995, a much larger facility based on a bandshell design.

[21] In the seasons of 1988 and 1989, Patti Starr, Ontario Place chair, reduced the deficit by $1.4 million by privatizing retail sales and fast-food operations, cutting advertising and increasing fees.

[citation needed] The results of this effort generated an improvement in attendance numbers, park revenues, and public perceptions of Ontario Place in 2011.

[citation needed] In the summer of 2010, the Government of Ontario issued a Request for information calling for ideas from private bidders to completely redevelop the park.

[33] Following the provincial elections in June 2014, the government announced the plans in July for Ontario Place to be developed as an urban parkland with Molson Canadian Amphitheatre, Cinesphere and the pods retained.

In response to the Province of Ontario's international call for development proposals, the WMF listing demanded “an end to top-down decision-making and the embrace of heritage to encourage community dialogue”.

"[50] Therme Canada's local partners are the Toronto International Film Festival (TIFF), Mississaugas of the Credit First Nation, Black North Initiative.

Formerly, Swim Drink Fish Canada was a partner, but has exited the partnership in the belief that the government's portion of the plan is "simply too opaque and controversial for us to support".

For 2012, based on strong reviews and rising attendance, Live Nation increased substantially the number of concerts scheduled for Echo Beach, including Our Lady Peace, Sam Roberts, and Counting Crows.

[58] Downtown Toronto's only beach, located at Ontario Place, also features an outdoor classroom (known as the "TeachBeach") which is also the venue of the annual Water-Human-Computer Interaction (WaterHCI) (de)conference.

Featured events included an annual Toronto Symphony rendition of Tchaikovsky's 1812 Overture, complete with the firing of the guns from the nearby HMCS Haida, and often performances by well established acts, such as B.

King, Peter Tosh, Glen Campbell, Kenny Rogers, Johnny Cash, James Brown, Dizzy Gillespie, Jan & Dean, Pat Metheny, Blondie, Chic T, KC and the Sunshine Band and Canadian acts like Burton Cummings, Lighthouse, Bruce Cockburn, The Nylons, Luba, Men Without Hats, The Box, Doug and the Slugs, Parachute Club, Red Rider and Strange Advance.

Unfortunately, due to a riot by Teenage Head fans in 1980 (purportedly instigated by their manager, who allegedly was interested in the publicity) harder rock acts were thereafter banned from the venue.

In summer of 1983, the Forum was ahead of the curve by bringing in acts like Paul Young and the Royal Family and Tina Turner just before her huge comeback the following year.

Sellers also said that Ontario Place was looking forward to an increase in attendance at the park, which cost the provincial treasury $4.5 million annually, 30% of its budget, an amount it wanted to decrease.

It was used in Star Trek: Strange New Worlds' first-season episode "Ghosts of Illyria", doubling for exterior shots of the abandoned Hetemit IX colony.