Cynthia Sonnier


Cynthia Sonnier is a partner in the Lafayette and New Orleans offices of Lewis Brisbois and a member of the General Liability and Marine & Energy Practices. Cynthia's defense litigation practice primarily focuses on the general casualty field with emphasis on automobile, trucking, admiralty and maritime, oil and gas, insurance, public entity and business litigation, in addition to the defense of workers’ compensation claims on behalf of private businesses and public municipalities and LHWCA claims. She has also successfully defended products liability claims including asbestosis, trichloroethylene, benzene and butadiene exposure litigation and has handled cases throughout the state of Louisiana. Over the course of her 23 year career, she has tried many jury and judge trials to verdict. The cases she has handled have involved amounts in controversy ranging from as low as $10,000 to as high as $22,000,000. She was recently named a 2019 Top Lawyer in the Acadiana area by Acadiana Profile Magazine and was the only female attorney listed in the Admiralty and Maritime Law division.

Primary Area(s) of Practice

  • General Liability
  • Marine & Energy
  • National Trial Practice
  • Asbestos Litigation

Additional Experience



All Louisiana District Courts, Appellate Courts and Supreme Court

United States District Court, Western District of Louisiana

United States District Court, Eastern District of Louisiana

United States District Court, Middle District of Louisiana

United States Fifth Circuit Court of Appeals


  • Lafayette Parish Bar Association
  • Louisiana State Bar Association
  • Fifteenth Judicial District Bar Association

Awards & Honors

Named “Top Lawyer” in Admiralty & Maritime Law by Acadiana Profile magazine in 2019


Louisiana State University

Juris Doctor, 1996

  • Student Bar Association- Executive Vice President
  • First Student Liaison to The Dean Henry George McMahon American Inn of Court

Louisiana State University

Bachelor of Arts in Political Science and Psychology with a minor in English, cum laude, 1992

  • Phi Beta Kappa
  • National Honor Society
  • Golden Key Society

Published Opinions

  • Fuller v. D.L. Peterson Trust, et. al., 50,699 (La. App. 2 Cir. 6/22/16), 197 So.3d 244
  • Cashman Equipment Corp. v. Rozel Operating Co., et al, 854 F.Supp.2d 406 ( E.D. La. 2012)
  • Munar v. State Farm Insurance Company, 07-611 (La. App. 3 Cir. 12/19/07), 972 So.2d 1273
  • Breaux v. Brown, 2006 U.S. Dist. LEXIS (W.D. Dec, 18, 2006)