Mark graduated summa cum laude from Illinois College and earned his law degree from Southern Illinois University School of Law where he was a member of the Moot Court Board. Following law school, Mark served the public for five years as a McLean County Assistant Public Defender and Sangamon County Assistant State’s Attorney. He is a seasoned litigator having prosecuted and defended hundreds of cases during that time. Mark returned to his hometown of Carrollton in 2018 to form Gillingham Law Office with his father, Richard. He has built a reputation as a sharp trial lawyer and innovative negotiator, capable of navigating a wide variety of complex legal matters for his clients.

Mark lives in Carrollton with his wife and daughters, enjoying the small-town way of life and cherishing time with his family. He is active with the Carrollton High School Fellowship of Christian Athletes, serves as moderator of his church, and coaches T-Ball and basketball.