Justice Mark Holmes Colbert was born Sept. 17, 1957, in Sulphur, Oklahoma, to Dixie and Ruby Colbert. He has four brothers and one sister. His brother, Scott Colbert, currently serves as the Gaming Commissioner for the Chickasaw Nation.
Justice Colbert graduated from the University of Missouri with a Bachelor of Arts degree in 1979 and Oklahoma City University with a Juris Doctorate in December 1982. He has been in private practice doing civil trial work in Ardmore, Oklahoma, since May 1983.
He is a charter member of the Chickasaw Bar Association and was elected to the Chickasaw Nation Supreme Court in 2002. He served as Chief Justice during the 2005-2006, 2008-2009, 2011-2012, 2014-2015, 2015-2016 and 2018-2019 terms. He is admitted to practice before the Oklahoma Supreme Court, the United States District Court for the Eastern, Western and Northern Districts of Oklahoma and the Northern District of Texas.
He married Kim Colbert in 1983. They have two daughters, Kathryn and Caroline and a grandson, Benjamin.