Mark Thomas Langston was born on January 3, 1959 in Columbus, Ohio, and grew up near Washington, D.C. After graduating from Winston Churchill High School in Potomac, Maryland (Class of 1977), he moved to Colorado, where he has lived since. He is married to Boulder Family Law Attorney Carol Glassman, and has an eight-year old son, Eli Langston. When not defending the criminally accused, Mark is involved in his son's academic and athletic activities, and enjoys skiing, surfing, cycling, hiking, fly-fishing, travel, photography and cooking.

Mark Langston and his family are members or supporters of the University of Colorado Alumni Association and Golden Buffalo Scholarship Fund, Boulder Valley YMCA, Temple Har Hashem, Countryside Montessori School, Douglass Elementary School, Louisville Youth Baseball Association, Eldora Ski and Snowboard Club, United States Ski Association, United States Ski Team, CUBAN Ski Team, Porsche Club of America, Boulder Jazz Dance Workshop, Colorado Ballet, Hospice of Boulder County, Foothills United Way, Boulder Shelter for the Homeless, Emergency Family Assistance, Community Food Share, Denver Rescue Mission, and Dental Aid of Colorado.