Dewdney may refer to:
- Dewdney, British Columbia, an unincorporated community, formerly a district municipality, in the Fraser Valley of British Columbia
- Dewdney (electoral district), a former electoral district in British Columbia, Canada
- Dewdney-Alouette Regional District, a former regional district in British Columbia, Canada
- Regina Dewdney, a federal electoral district in Regina, Saskatachewan, Canada.
- The Dewdney Trail, an important colonial-era route across southern British Columbia from Hope in the Fraser Valley to Wild Horse Creek in the East Kootenay.
- The Dewdney Trunk Road, one of the earliest main roads in the Lower Mainland of British Columbia and today a series of arterial routes between Port Moody and Mission
People with the surname Dewdney:
- Alexander Dewdney (born 1941), Canadian mathematician, computer scientist and philosopher
- Christopher Dewdney (born 1951), Canadian poet
- Edgar Dewdney (1835–1916), Canadian surveyor, engineer, politician, and provincial Lieutenant-Governor
- Selwyn Dewdney (1909–1979), Canadian author, illustrator and artist, father of Alexander and Christopher
- Tom Dewdney (born 1933), West Indian cricketer