Douglas M. Brewster grew up in Bossier City, Louisiana, and attended the University of Southwestern Louisiana (now known as the University of Louisiana-Lafayette). He completed his BFA degree in 1978, and Washington State University in Pullman, Washington, awarded him a teaching fellowship for MFA studies. He finished his MFA degree in 1980, married, and moved to Houston, then Lafayette. Brewster’s first major show was in1985 at the University Art Museum in Lafayette in 1985.
In 1987 Brewster moved to New Orleans to pursue teaching and art. In 1991 he was the Project Director of the New Orleans Contemporary Art Center’s “Artists on War” exhibition.
Brewster exhibited regularly at area galleries and institutions and taught Talented Visual Arts in the Orleans and St. Tammany Parish public schools. In 1994 he was awarded a NEA/SAF individual artist fellowship, followed by an Art Matters Fellowship in Painting.
Brewster's October 2006 exhibition at Barrister’s Gallery was among the first art exhibits in New Orleans after the flood. He went to work as a fine arts instructor at Delgado Community College until his retirement in 2017. He lives in Covington, Louisiana, and continues to create art at his studio there.