St. Anthony, ID has a population of 3,488 and is the 8,062nd largest city in the United States. The population density is 2,256 per sq mi which is 11722% higher than the Idaho average and 2390% higher than the national average. The median age in St. Anthony is 34 which is approximately 4% lower than the Idaho average of 36. In St. Anthony, 65% of the population over 15 years of age are married, 86% speak English and 11% speak Spanish. 59% of St. Anthony residents were born in Idaho, 34% were born out of state, 1% were born outside of the United States and 6% were foreign born.