Port Austin, MI. Online Offers. Port Austin is a village in Huron County in the U.S. state of Michigan. The population was 737 at the 2000 census. The village is within Port Austin Township. As of the census of 2000, there were 737 people, 370 households, and 206 families residing in the village. The population density was 733.7 per square mile (284.6/km²). There were 622 housing units at an average density of 619.2 per square mile (240.2/km²).