From downtown Toronto, take the Don Valley Parkway North and follow the signs from Don Mills Road North.
If you are not coming from downtown, use Highway 401 (or 404), then take the Don Valley Parkway South and exit at Wynford Drive. Head west on Wynford Drive and watch for the Ontario Science Centre signs!
From downtown Toronto, take the Yonge Street subway line north to the Eglinton station and transfer to the Eglinton East bus. Get off at Don Mills Road.
Or, take the Bloor-Danforth subway line east to the Pape station and transfer to the Don Mills bus. Get off at St. Dennis Drive, right in front of the Ontario Science Centre.