Arthur, ND has a population of 341 and is the 21,769th largest city in the United States. The population density is 223 per sq mi which is 2153% higher than the North Dakota average and 146% higher than the national average. The median age in Arthur is 51 which is approximately 45% higher than the North Dakota average of 35. In Arthur, 64% of the population over 15 years of age are married, 98% speak English and 0% speak Spanish. 67% of Arthur residents were born in North Dakota, 32% were born out of state, 1% were born outside of the United States and 1% were foreign born.