Government of Canada Open Data portal, which includes data from various government departments. Some data of interest:
Municipal open can be found from the Municipal Open Data Portals in Canada
Quickly access data from Natural Resources Canada (NRCan's) Geogratis program. Includes the following datasets:
Some popular datasets such as data from DMTI Spatial Inc, Statistics Canada are available to uOttawa students, faculty and researchers on Scholars Geoportal. You must log-in to the Portal to download the data.