Mark Rush Williamson

Mark Rush Williamson is a family law attorney and Partner at Sullivan, Klocke & Williamson, P.C. in Dallas, Texas. Mr. Williamson represents clients throughout Texas and represents folks from all walks of life, including educators, business owners, physicians, attorneys, ranchers and retirees. He is passionate yet kind, always seeking the best resolution even at the beginning of a case. His practice includes divorce, mediation, asset division, custody, child support, grandparents’ rights, modifications, paternity, premarital and post marital agreements, relocation, temporary orders and protective order cases, to name a few. 

In his more than 35 years as a practicing attorney, Mr. Williamson has guided many Texas residents through complex family law issues. He keeps his client base small to provide personal attention to each client and work toward the best possible resolution to their unique cases. 

Regarded for his high legal capability and ethical standards, Mr. Williamson is AV Preeminent peer-review rated – the highest rating – through Martindale-Hubbell. 

Active in his legal community, Mr. Williamson is a member of the Collin County Bar Association, and the family law sections of the Dallas Bar Association and the State Bar of Texas. He is a barrister in the American Inns of Court and belongs to the Phi Delta Theta fraternity. Additionally, Texas Monthly magazine included him on its Top Lawyers of Texas list several years in a row.

In 1982, Mr. Williamson graduated from Baylor University with a bachelor’s degree in accounting. He earned his law degree from the University of Texas at Austin School of Law in 1985. He is qualified to practice law before all Texas state courts, the U.S. District Court for the Northern District of Texas and the U.S. Tax Court.