Experienced California Trial Lawyer

Gregory A. Thyberg Founder
Email: Greg Thyberg  
Phone:  916.204.9173   

Gregory Thyberg was admitted to the California State Bar in 1981. Mr. Thyberg began his legal career as a criminal prosecutor where he spent several thousand hours in the courtroom examining hundreds of witnesses. In 1986, Mr. Thyberg entered civil practice representing banks and financial institutions when Dinkelspiel & Dinkelspiel, one of San Francisco’s oldest law firms, hired him as an associate. Over the past thirty years, Mr. Thyberg’s practice has encompassed a broad range of legal matters including business and commercial disputes, insurance law and employment law. Mr. Thyberg’s litigation experience includes opening a house counsel office for a major insurance company in Southern California where he was responsible for supervising a staff of attorneys in handling more than 400 litigation files. 

Mr. Thyberg is currently representing a whistleblower in the case of United States ex rel Brian Markus v. Aerojet Rocketdyne Holdings, Inc. et. al., Case No, 2:15-cv-224  (E.D. Cal), that has been listed by the Thomson Reuters legal news website Law360.com as one of the top government contracts cases of 2019. Bloomberg Government has cited this case as one of the top five big federal contract cases to watch in 2020. The lawsuit, which lawyers have referred to as sending shock waves throughout the defense industry, alleges that Aerojet Rocketdyne obtained billions of dollars in government contracts related to military and space technology, while making false statements to conceal the fact it was less than 25% compliant with legally mandated and contractually required cyber security controls. 

Mr. Thyberg has tried over 55 jury trials to verdict in courts throughout the State of California and has argued  multiple cases before the California Court of Appeal. He is admitted to practice before the United States District Courts for the Northern, Eastern and Central Districts of California. In recognition of his trial experience and professional reputation for civility and ethics, Mr. Thyberg has been elected by his peers to the American Board of Trial Advocates (“ABOTA”). Mr. Thyberg served for ten years as a faculty member for the University of California, Hastings College of Trial and Appellate Advocacy where he taught trial skills to practicing attorneys. Mr. Thyberg has also held a faculty appointment as a lecturer at the University of California, Davis, School of Law where he taught arbitration, mediation and negotiation skills. 

Mr. Thyberg has served as mediator for more than 20 years and has completed 42 hours of mediation training at the Pepperdine University’s Straus Institute for Dispute Resolution. He has served as a Judge Pro Tem/Settlement Officer for the Sacramento, San Francisco and Los Angeles County Superior Courts. 

Mr. Thyberg has been a lecturer for various continuing legal education programs, including seminars sponsored by the Bay Area Legal Secretaries Forum, Legal Secretaries, Inc. and San Francisco Trial Lawyer’s Association. He has also appeared on several national news programs including the CBS Early Show, Fox News, The Big Story with John Gibson, and Geraldo Rivera Live. 

Mr. Thyberg earned his B.A. degree from the University of California Berkeley with High Honors in Economics and Distinction in General Scholarship in 1978. He earned his J.D. from UC Davis Law School in 1981 and an LL.M. in International Law from The London School of Economics and Political Science, University of London, England in 1982. In 2006, Mr. Thyberg earned an M.A. degree in Christian Apologetics, with High Honors, from Biola University. 

  • Employment Law
  • Whistleblower/Qui Tam
  • Litigation
  • Arbitration
  • Mediation

Admitted to Practice

  • California, 1981


  • University of California School of Law, Davis, J.D., 1981
  • The London School of Economics and Political Science, University of London, LL.M., 1982
  • University of California, Berkeley, B.A., with high honors in Economics, distinction in general scholarship, 1978
  • Biola University, M.A., with high honors in Christian Apologetics, 2006

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Sacramento Office

770 L St
Ste 950
Sacramento, CA 95814

Open Today 9:00am - 5:00pm

Available 24/7 by appointment


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