Mentor is located at 41°39'56" North, 81°20'21" West (41.665833, -81.339444).
According to the United States Census Bureau, the city has a total area of 28.08 mi2 (72.72 km2). 26.77 mi2 (69.33 km2) of it is land and 1.31 mi2 (3.38 km2) of it is covered by water. The total area is 4.65% water.
Mentor is located in the Eastern Standard Time (EST) timezone, GMT-05:00. It observes Daylight Saving Time (DST).