Ardoch is a city in Walsh County, North Dakota, United States. The population was 31 at the 2020 census. Ardoch, named for the comm…Ardoch is a city in Walsh County, North Dakota, United States. The population was 31 at the 2020 census. Ardoch, named for the community of Ardoch, Ontario, was founded in 1881. According to the United States Census Bureau, the city has a total area of 0.26 square miles, all land.