Mentor (MEN-(t)ər) is a city in Lake County, Ohio, United States. Mentor was first settled in 1797. The population was 47,159 at the 2010 census. In July 2006, CNNMoney.com ranked Mentor 68th in a list of the Top 100 Best Places to Live in America. Just four years later in July 2010, CNNMoney.com ranked Mentor 37th on the same list.In 1876 James A. Garfield purchased a home in Mentor, from which he conducted the first successful front porch campaign for the presidency.