One of 99 counties in Iowa, United States. County seat: Sidney.
One of 44 counties in Idaho, United States. County seat: St. Anthony.
One of 23 counties in Wyoming, United States. County seat: Lander.
One of 64 counties in Colorado, United States. County seat: Cañon City.
An unincorporated community in Hillsborough County, Florida, United States.
The state capital of New South Wales, Australia, and the most populous city in Australia.
A seaport and former city in Nova Scotia, Canada, now part of the amalgamated Cape Breton Regional Municipality on Cape Breton Island.
A surname from Old English, a spelling variant of Sidney.
A unisex given name transferred from the surname.