Centennial Planetarium, Planetarium in Calgary, Canada.

Centennial Planetarium is a Brutalist building of raw concrete at 701 11 Street SW in Calgary, designed by McMillan Long and Associates with a non-orthogonal layout around a central bay. Its west wing held a 255-seat celestial theatre with a 65-foot domed screen, and its east wing a 250-seat lecture hall. Since 2019 it houses Contemporary Calgary, a public art gallery.

The building opened in 1967 as part of Canada's centennial celebration, after architectural firm McMillan Long and Associates won a design competition. It later housed the Hangar Flight Museum between 1971 and 1985 before being transformed into the Science Centre.

The building's name comes from the Canadian Centennial of 1967, when Calgary built it as a civic planetarium. Its Brutalist concrete form won the National Design Council Concrete Award in 1967 and the Massey Medal in 1970. Since 2019 it has housed Contemporary Calgary, which mounts exhibitions such as Charles Stankievech's The Desert Turned to Glass, engaging the building's scientific past.

The building stands at 701 11 Street SW, north of Mewata Armouries above the Bow River; the 2010 removal of part of the south parking structure made way for the CTrain west line. The City of Calgary and Lemay renovated the interior, adding a 10,000 sq ft gallery, a 3,000 sq ft gallery, an entrance pavilion, a restaurant and a rooftop sculpture garden. As of 2019 the gallery opened to the public two days a week while work continued.

The building has received multiple awards for its architectural design and stands as one of Canada's finest examples of brutalist architecture. Its unusual form with non-orthogonal walls was revolutionary at its creation and continues to fascinate visitors today.