St. Joseph, MO has a population of 76,901 and is the 457th largest city in the United States. The population density is 1,747 per sq mi which is 1923% higher than the Missouri average and 1829% higher than the national average. The median age in St. Joseph is 36 which is approximately 7% lower than the Missouri average of 38. In St. Joseph, 51% of the population over 15 years of age are married, 93% speak English and 4% speak Spanish. 70% of St. Joseph residents were born in Missouri, 24% were born out of state, 1% were born outside of the United States and 4% were foreign born.