Mentor is a city in Polk County, Minnesota, United States. It is part of the 'Grand Forks-ND-MN Metropolitan Statistical Area'. The population was 153 at the 2010 census. The city is located near Maple Lake.
According to the United States Census Bureau, the city has a total area of 1.9 square miles (4.9 km²), all of it land.
As of the census of 2000, there were 150 people, 82 households, and 45 families residing in the city. The population density was 79.3 people per square mile (30.6/km²). There were 102 housing units at an average density of 53.9 per square mile (20.8/km²). The racial makeup of the city was 100.00% White.