Blaine, formerly known as Blaine's Crossroads, is a city in Grainger County, Tennessee, United States, and a suburb of neighboring Kno…Blaine, formerly known as Blaine's Crossroads, is a city in Grainger County, Tennessee, United States, and a suburb of neighboring Knoxville. It is part of both the Knoxville Metropolitan Statistical Area and the Morristown Metropolitan Statistical Area. The population was 2,084 at the 2020 census.