Canada's equivalent to Counties are known uniformly as Census Divisions which are called by different names in different provinces, or in different parts of provinces. The below table shows the largest and smallest Census division in Canada and the provinces and territories by area and by population respectively.

10 fastest growing population (1996-2001)

1. York RM, Ontario 23.1%
2. Mirabel RCM, Quebec 20.8%
3. Division No. 16, Alberta 17.7%
4. Peel RM, Ontario 16.0%
5. Division No. 6, Alberta 15.9%
6. Division No. 8, Alberta 14.6%
7. Simcoe County, Ontario 14.3%
8. Squamish-Lillooet RD, British Columbia 12.3%
9. Dufferin County, Ontario 11.7%
10. Division No. 15, Alberta 10.6%

10 fastest shrinking population (1996-2001)

1. Division No. 3, Newfoundland and Labrador -13.8%
2. Division No. 8, Newfoundland and Labrador -12.6%
3. Skeena-Queen Charlotte RD, British Columbia -12.5
4. Division No. 2, Newfoundland and Labrador -12.1%
5. Division No. 9, Newfoundland and Labrador -12.1%
6. La Côte-de-Gaspé RCM, Quebec -11.1%
7. Division No. 4, Newfoundland and Labrador -10.7%
8. Mount Waddington RD, British Columbia -10.2
9. Division No. 7, Newfoundland and Labrador -10.1%
10. Guysborough County, Nova Scotia -10.0%

Census divisions of Canada | Statistics Canada