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Gregory A. Calvert

Mr. Calvert has been actively engaged in the practice of law in Tulsa, Oklahoma and surrounding venues since 1993, and has extensive litigation experience in Oklahoma's state and federal courts. 

Mr. Calvert represents both individuals facing family crises involving divorce, paternity, guardianship and related family law issues, and business entities engaged in commercial or construction disputes, confronted by liability claims involving tort or products liability claims, or facing railroad and transportation law issues.  He has served as a speaker at CLE meetings of the National Association of Railroad Trial Counsel and the former Texas Association of Railroad Trial Counsel.  

Mr. Calvert founded Calvert Law Office, PLLC in November, 2010, after resigning his position as a shareholder in one of Oklahoma's largest and most respected law firms.

Significant Achievements:

  • Served as co-lead counsel for a building products manufacturer in a series of construction defect and products liability lawsuits filed in Oklahoma, Texas and Missouri, and assisted in nationwide coordination of discovery and defense strategy in related suits filed across the country with alleged damages over $50 million.
  • Succeeded in shepherding a foreign corporate defendant based in Puerto Rico from default judgment to dismissal on jurisdictional grounds. Conley Corporation v. Indusa, Inc., 2006 WL 266595 (N.D. Ok.) (Slip Copy).
  • Successfully defended German manufacturer in multi-million dollar products liability action. 189 Fed. Appx. 782, 2006 WL 2065069 (10th Cir. 2006).
  • Obtained summary judgment in defense of National Rails to Trails Act litigation involving multiple plaintiffs.
  • Obtained numerous summary judgments in defense of Class I and Short Line railroad clients.
  • Successfully defended corporate defendant against business tort and intentional infliction of emotional defense claims, obtaining a directed verdict at the close of plaintiff's case.
  • Teamed with a small group of attorneys to successfully defend multiple healthcare facilities against claims brought by more than 1,200 individual plaintiffs in mass tort, medical device/malpractice action.
  • Obtained a 12-0 jury verdict on behalf of a defendant law firm in connection with claimed violations of Section 362 of the United States Bankruptcy Code.

Practice Areas

  • Appellate Practice (both civil and domestic)
  • Construction Contracts/Litigation
  • Corporate/Commercial Litigation
  • Divorce & Family Law, including:
    • Child Custody
    • Child Support
    • Dissolution of Marriage
    • Division of Assets and Liabilities
    • Legal Separation
    • Guardianships
    • Pre-Marital (Antenuptial) Agreements
    • Paternity
    • Protective Orders
    • Spousal Support
  • Products Liability Litigation
  • Railroad and Transportation Litigation
  • Real Estate Contracts/Disputes
  • Tort & Insurance Litigation


  • 1993 - Oklahoma Supreme Court (all Oklahoma counties)
  • U.S. Court of Appeals for the Tenth Circuit
  • U.S. District Courts for the Northern, Eastern and Western Districts of Oklahoma
  • Multiple pro hac vice admissions in Texas and Missouri State Courts


  • 1990 - Oklahoma State University, B.S., Business Administration (Economics)
  • 1993 - University of Oklahoma College of Law, J.D., with honors

Professional Affiliations

  • Oklahoma Bar Association
  • Tulsa County Bar Association
  • National Association of Railroad Trial Counsel
  • Oklahoma Association of Defense Counsel
  • Defense Research Institute

Community Involvement

  • Member, Bishop Kelley High School Advisory Council, 2008-2011
  • Member, Christ the King Catholic Church