Downsview Airport, formerly IATA: YZD, ICAO: CYZD, was an airport located in Toronto, Ontario, Canada. An air field, then air force base, it has been a testing facility for Bombardier Aerospace from 1994. In 2018, Bombardier sold the facility to Northcrest Developments; in late 2023, Northcrest announced that industrial and airport operations would close by mid-2024, as redevelopment into commercial and residential properties moves forward. The airport was listed as closed March 7, 2024.

Downsview Airport had its own fire service (Bombardier Aerospace Emergency Services) which covered airport operations (using two airport fire rescue vehicles) and plant operations (using two SUV emergency vehicles). Bombardier Emergency Services employees were cross-trained as firefighters, first responders and airport security.