Thornton was born in 1976 and raised in Aiken, South Carolina. In the spring of 1999, Thornton received his BFA from the University of South Carolina in Columbia, SC. While at Carolina, he studied painting with Philip Mullen and Jim Steven.
Following college graduation, Thornton worked in a studio space at Gallery 701 in Columbia, SC. Gallery 701, a cultural center for visual and performing arts, once held one of the largest collections of Columbia, SC artists. In February 2000, Thornton had his first solo show at 701. It was in preparation for this show that he began using his 10 x 10 inch painting format.
In June 2000, Thornton moved to a family house in Modoc, SC, where he worked for a year. Thornton then moved to Chicago in August 2001 and was employed as Gallery Director at Mongerson Galleries and Assistant Preparator at Russell Bowman Art Advisory. While in Chicago, it became apparent that the South was a significant aspect of Thornton’s work and it ultimately lead him to return to Aiken in August of 2005. Currently, Brown Thornton lives and works in a warehouse studio in Aiken, South Carolina.