Seth GillenwaterYour Fierce Advocate® in Criminal Defense

Seth A. Gillenwater is a criminal defense attorney dedicated to advocating for individuals facing serious legal challenges. He brings a thoughtful, strategic approach to every case, combining strong legal analysis with a commitment to protecting his clients’ rights and guiding them through difficult situations.

Before joining Cannon & Associates, Seth served as Assistant General Counsel with the Oklahoma State Bureau of Investigation. In that role, he advised on complex legal matters involving criminal investigations, administrative law, and civil litigation. Working closely with law enforcement and investigators, he developed a deep understanding of how criminal cases are built from the ground up. He now uses that insight to identify weaknesses, challenge evidence, and advocate effectively for his clients.

Seth focuses his practice on criminal defense matters, including misdemeanors, felony cases, and expungements. He has particular experience with expungement law and is passionate about helping individuals clear their records and move forward with confidence. Known for his professionalism, attention to detail, and steady approach, Seth works to ensure that each client understands their options and receives a defense strategy tailored to their specific circumstances.

Seth earned both his Juris Doctor (J.D.) and a Certificate in Homeland Security Law from Oklahoma City University School of Law. He also holds both a Bachelor of Science (B.S.) and an Associate in Science (A.S.) degree from Langston University. 

At Cannon & Associates, Seth is part of a team committed to preparation, collaboration, and delivering strong, client-focused advocacy when it matters most. He takes pride in standing beside his clients and providing clear guidance and determined representation throughout every stage of the legal process.