Hamilton is a city in Pembina County, North Dakota, United States. The population was 46 at the 2020 census. Hamilton was platted in 1882…Hamilton is a city in Pembina County, North Dakota, United States. The population was 46 at the 2020 census. Hamilton was platted in 1882, when the railroad was extended to that point. The city took its name from Hamilton, Ontario, the native land of a large share of the early settlers. A post office has been in operation at Hamilton since 1879. Hamilton is the home of the Pembina County Fair, the oldest continuously running county fair in North Dakota since 1894. Hamilton is also the home of The Bank of Hamilton, the oldest state bank in North Dakota, founded in 1886.