William M. Mattes


Bill is an experienced litigator who focuses his practice on complex commercial litigation, including high-stakes business disputes and bet-the-company matters. He handles litigation in the financial services industry for clients including banks, factoring companies, mortgage lenders, and other secured lenders. He has decades of experience with construction litigation, and has favorably settled several multi-million dollar construction-related disputes. He regularly draws upon his knowledge of construction law to counsel companies on their plans, and to assist in all phases of litigation, government investigations, and business counseling that can arise from OSHA investigations.

He regularly counsels clients on general business and growth issues including expansion into new markets. This includes franchisor & franchisee matters, distribution and logistics issues, site selection, insurance issues, regulatory issues, and licensing requirements. He was personally involved with litigation, arbitration, and contract interpretation for three of the largest public works projects in Ohio, and he has represented several Ohio universities in matters including commercial disputes, construction disputes, and supplier and vendor contract issues. Bill also counsels boards, shareholders, and senior management of for-profit and not-for-profit entities on risk management and litigation issues.

Understanding that every client has unique needs and tolerances, Bill works closely with clients to build a litigation strategy that fits their objectives, whether negotiating alternative dispute resolutions or preparing for trial. His litigation experience is wide-ranging, including serving on litigation teams as special counsel to the Ohio attorney general, as well as handling appeals before the Ohio Supreme Court. He also has secured victories for clients in an array of high-stakes litigation, including one in which he obtained a multi-million dollar verdict on behalf of a client in a complicated series of financial transactions and prevailed on appeal. He also secured a $2 million verdict for his client in a complex trade secrets case that also involved elements of tortious interference and civil conspiracy. Recently he secured a verdict in excess of $1 million for a national bank in a disputed commercial loan, in which the bank prevailed and was awarded their attorneys’ fees.

He has been a speaker at professional seminars offered by Lorman Educational Services, the Columbus Bar Association, Cincinnati Bar Association, Sterling Educational Services and HalfMoon, LLC.


  • Ohio Northern University, Claude W. Pettit College of Law  (J.D., 1988)
    • Law Review
    • Moot Court
    • Constitutional Law Book Award
  • Southern Connecticut State University  (B.S., 1985)
    • Political Science

Bar Admissions

  • Ohio

Court Admissions

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


  • Columbus Bar Association, 
    • Admissions Committee 
    • Construction Law Committee
    • Federal Courts Committee
  • No longer Ohio State Bar Association Member
  • Volunteer Lawyers for the Poor
  • Knights of Columbus, Our Lady of Peace, Council #14282, no longer advocate
  • Columbus Landmarks Foundation
    • Past secretary
    • Past board member
    • Past president
  • Northwest Swim Club, Past Board of Directors
  • Ohio Young Democrats 
    • Former counsel
    • Former Executive Board member


  • Ohio Super Lawyers®  (2014 - Present)
    • For Business Litigation (2021)
  • Forty Under Forty by Business First (1998)
  • Former assistant attorney general, Court of Claims Defense Section (1988 - 1992)