William J. Seitz, III

Partner Of Counsel

As both a respected state legislator and an accomplished litigator, Bill brings unique experience and perspective to clients. He has more than 40 years of experience handling a wide range of matters, ranging from antitrust proceedings to franchise and distribution law. As a long-time leader in supporting criminal and civil justice reform, he is able to draw upon his knowledge to help clients navigate through complex regulations and resolve disputes efficiently.

He has practiced antitrust law for more than 40 years and was recognized in 2014 by Best Lawyers©as Southwest Ohio’s Antitrust “Lawyer of the Year.” Bill served on the Board of Governors of the Antitrust Section of the Ohio State Bar Association and has litigated antitrust cases in Ohio, Pennsylvania, Tennessee, and Florida. While serving in the State General Assembly, he successfully amended Ohio’s antitrust statutes and has represented numerous nationally and internationally known corporations in counseling or litigating antitrust matters.

Bill’s leadership abilities and knowledge of the justice system have also enabled him to become a valued leader in the State of Ohio, where he currently serves as majority leader in the Ohio House of Representatives. Previously, he served in the Ohio House for seven years, where he became majority whip, before joining the Ohio Senate in 2007 and then returning to the Ohio House in 2017. He has helped lead efforts to reform sentencing laws, reduce prison overcrowding, eliminate barriers to employment for non-violent offenders and enhance penalties for violent offenders. He also was an integral figure in helping usher in Ohio’s sweeping tort reform, which helped transform the state’s business landscape. His work led to him receiving the prestigious U.S. Chamber Institute for Legal Reform State Legislative Achievement Award in 2013. In 2019, Best Lawyers® named him Best Lawyer in Southwest Ohio for municipal litigation. 

Credentials

Education

University of Cincinnati College of Law (J.D., 1978)

University of Cincinnati (B.A., 1975)

Bar admissions

  • Ohio

Court admissions

  • U.S. Supreme Court
  • U.S. District Court
  • U.S. Court of Appeals for the Sixth Circuit
  • U.S. District Court for the Southern District of Ohio

Affiliations and memberships

  • Ohio House of Representatives, majority leader
  • American Legislative Exchange Council, Board of Directors
  • University of Cincinnati Law School, Board of Advisors
  • Hamilton County Transportation Improvement District
  • Ohio State Bar Association, Antitrust Section Board of Governors past member
  • Western Hills Country Club
  • Hamilton County Republican Party, Executive Committee
  • Fraternal Order of Police Associates
  • Westwood Civic Association, past president
  • Western Economic Council, past president
  • Cincinnati Recreation Commission, past commissioner
  • Invest in Neighborhoods, past trustee

Distinctions

  • Best Lawyers®
    • “Lawyer of the Year” in Cincinnati for Litigation – Municipal (2020)
    • Antitrust Law, Commercial Litigation, Litigation – Municipal (2021-2024)
  • U.S. Chamber Institute for Legal Reform State Legislative Achievement Award (2013)
  • The Power 100 by Cincy Magazine (2012 – 2014)

Career Highlights
  • Counseled Leading ULT Freezer Company through Merger

    We counseled our client, Stirling Ultracold, an innovative developer and manufacturer of ultra-low temperature (ULT) freezers for life science and biopharma research, through its merger with BioLife Solutions, Inc., a developer focused on bioproduction devices used in cell and gene therapies. The all-stock mergers was in excess of $230 million.

    Stirling’s CEO saw the potential for increased demand for the company’s freezers during the COVID-19 pandemic as the freezers were a direct competitor to dry ice used in storing the COVID-19 vaccine. Merging with BioLife enabled Stirling to execute an aggressive strategic plan marketing and selling its freezers. Dinsmore served as the company’s general counsel since 2019, and our team of attorneys brought experience in mergers and acquisitions, labor, insurance, and life sciences, all of which was necessary to fully understand and address the company’s specialized needs. We counseled our client through the merger while simultaneously defusing challenges. Our team’s collective experience enabled Stirling’s executives to address the company’s short-term needs while also achieving its long-term goal.

    “The entire team at Dinsmore was, by far, the best engagement I have had in the 15-plus strategic transactions I have done throughout my career,” said previous Stirling Ultracold CEO Dusty Tenney, now COO and president at BioLife. “Their responsiveness, engagement, availability and deal leadership were extraordinary from LOI to closing.”

News
  • August 21, 2025

    260 Dinsmore Attorneys Listed as 2026 Best Lawyers®, Ones to Watch

  • December 20, 2024

    Dinsmore Attorneys Help Secure Ohio Supreme Court Ruling in Opioid Case

  • August 15, 2024

    250+ Dinsmore Attorneys Named 2025 Best Lawyers ®, Ones to Watch

  • August 17, 2023

    200+ Dinsmore Attorneys Named 2024 Best Lawyers®, “Ones to Watch”

  • March 30, 2023

    Dinsmore’s Corporate Team Closes Two Substantial Deals for Clients in March

  • August 18, 2022

    2023 Best Lawyers® List Recognizes 190 Dinsmore & Shohl Attorneys

  • August 19, 2021

    Best Lawyers® Recognizes 191 Dinsmore & Shohl Attorneys

  • August 20, 2020

    Best Lawyers® Recognizes 180 Dinsmore & Shohl Attorneys