Greg Marks

Greg Marks

Slack Davis Sanger, LLP

Recognized since 2016

Dallas, Texas

Practice Areas

Personal Injury Litigation - Plaintiffs

Product Liability Litigation - Plaintiffs

Lawyer of the Year Badge - 2021 - Product Liability Litigation - Plaintiffs
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Greg Marks has dedicated the last 20 years to helping victims who have suffered serious, catastrophic injuries. He understands the emotional, financial, and physical pain caused by an unexpected accident and takes care to guide his clients through this trying time. He has built his reputation through providing compassionate, personal service and creative, expert legal representation.

Greg has dedicated his law practice to helping victims who have been injured as a result of negligence, defective, and dangerous products and by the conscious disregard of safety products. He is Board Certified in Personal Injury Trial Law by the Texas Board for Legal Specialization and has done extensive legal work in exposing vehicle and product defects and enacting changes that ultimately save lives. As a family man, he understands the challenges his clients may be facing and is committed to guiding them every step of the way. He takes great pride in his personal service and is dedicated to a client-focused approach to the law.

Greg is a Past President of the Dallas Trial Lawyers Association and currently serves on the Board of the Texas Trial Lawyers Association (TTLA). He is a member of the American Board of Trial Advocates and is an AV®-rated attorney (Martindale-Hubbell Peer Review Ratings). He has been repeatedly been named to Best Lawyers and Super Lawyers and was named “Lawyer of the Year” in Plaintiff’s Product Liability in 2020 by Best Lawyers. He is a member of the Million Dollar Advocates’ Forum, the Dallas Bar Association, the TTLA, and the American Bar Association. He has been admitted to practice law before all state and federal courts in Texas, the Northern District of Indiana, the Western District of Louisiana, the Southern District of New York and the United States Judicial Panel on Multidistrict Litigation.

Prior to practicing law, Greg served as a civil engineer for an offshore drilling company. After changing career paths and graduating in the top 15% of his class in law school, he held a position with a prestigious Dallas law firm, representing corporate clients and businesses. Through this early experience, Greg developed his talent for preparing and trying complex lawsuits and jury trials. While it was a lucrative position, he wanted to use his talents and experience to help individuals and make a positive impact on their lives. So, for more than two decades, he has followed his passion of helping individuals by serving as a personal injury lawyer and fighting for victims of car accidents, vehicle defects, truck accidents, construction accidents, wrongful death, and other catastrophic accidents. In 2011, Greg joined with his longtime friend and colleague, Mike Guajardo, to form Guajardo & Marks, L.L.P. In 2021, Guajardo & Marks merged with Slack Davis Sanger.


  • 3500 Maple Avenue, Suite 1200
    Dallas, TX 75219


  • Southern Methodist University

Lawyer of the Year Badge - 2021 - Product Liability Litigation - Plaintiffs

Named "Lawyer of the Year" by Best Lawyers® for:

  • Product Liability Litigation - Plaintiffs, Dallas/Fort Worth (2021)

Recognized in The Best Lawyers in America® 2023 for work in:

  • Personal Injury Litigation - Plaintiffs
  • Product Liability Litigation - Plaintiffs

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