Guy A. Thiessen

Guy A. Thiessen, the managing partner of GT Law Firm, located in Tulsa, Oklahoma, is a seasoned attorney with over three decades of experience in the health care liability field. His personal injury practice area extends to the fields of nursing home abuse and neglect, wrongful death and medical malpractice.

Beginning his legal career at an insurance defense firm, Mr. Thiessen soon discovered his true passion lay in advocating for injured victims and their families. In 1990, he transitioned to a small personal injury firm, and by 1992, he had established his own practice, dedicated to serving those who have suffered due to negligence.

Mr. Thiessen's practice benefits from his extensive litigation background and his insightful understanding of insurance company tactics. He has assisted countless clients in effectively navigating the complexities of claims and lawsuits, striving to secure the maximum settlement amounts and ensuring accountability for those responsible for serious injuries or fatalities. His approach is characterized by a calm, thoughtful demeanor and a grounded perspective, which he employs to meticulously evaluate each case and pursue justice for his clients.

Acknowledged by his peers, Mr. Thiessen has achieved an AV Preeminent peer-review rating* through Martindale-Hubbell, reflecting his high standards in legal ability and ethical conduct. His professional achievements include admission to all Oklahoma and Arkansas federal courts, the U.S. Court of Appeals for the 8th and 10th Circuits and the United States Supreme Court. His leadership within the legal community is evidenced by his tenure as past president and long-standing membership in the Oklahoma Association for Justice (OAJ), along with his service as the OAJ State Delegate to the American Association of Justice (AAJ).

Additionally, Mr. Thiessen actively contributes to legal education, frequently speaking at seminars to instruct fellow attorneys on handling cases involving nursing homes and assisted living facilities. His academic background includes a Bachelor of Science in finance from Oklahoma State University and a Juris Doctor from Oklahoma City University School of Law. Licensed to practice law in both Oklahoma and Arkansas, he remains committed to advocating for justice and supporting his clients through the legal process.

*AV®, AV Preeminent®, Martindale-Hubbell Distinguished and Martindale-Hubbell Notable are certification marks used under license in accordance with the Martindale-Hubbell certification procedures, standards and policies. Martindale-Hubbell® is the facilitator of a peer-review rating process. Ratings reflect the anonymous opinions of members of the bar and the judiciary. Martindale-Hubbell® Peer Review Ratings™ fall into two categories – legal ability and general ethical standards.