Erhard is a city in Otter Tail County, Minnesota, United States. The population was 148 at the 2010 census.
According to the United States Census Bureau, the city has a total area of 0.6 square miles (1.5 km²), of which, 0.5 square miles (1.4 km²) of it is land and 0.04 square miles (0.1 km²) of it (3.57%) is water.
As of the census of 2000, there were 150 people, 71 households, and 39 families residing in the city. The population density was 276.4 people per square mile (107.3/km²). There were 73 housing units at an average density of 134.5 per square mile (52.2/km²). The racial makeup of the city was 98.00% White and 2.00% Native American.