Sean Patrick O'Neill

Sean O’Neill is a trial lawyer specializing in catastrophic personal injury, elder abuse, wrongful death, managed care liability, and medical malpractice matters on behalf of Plaintiffs throughout California.

Sean was born and raised in Carlsbad, California. He is a graduate of the University of Arizona and Pepperdine University School of Law. While in law school, Sean clerked in the United States Senate, Judiciary Committee, the Los Angeles County District Attorney’s office and for a number of high-profile litigation firms in Los Angeles. Mr. O’Neill was also selected to serve as a special editor to the Harvard Journal of Law & Public Policy.

After law school Sean served as corporate counsel at United States Steel Corporation in Pittsburgh, Pennsylvania. Reporting directly to the General Counsel, Sean assisted with the Company’s international trade enforcement litigation, the Company’s engagement on public policy issues, and advised the business units on a number of high priority corporate matters. Thereafter, Sean returned to California to work as a trial lawyer at Reback, McAndrews, Kjar, Warford & Stocklaper where he defended medical and legal malpractice cases throughout the State. While Sean really enjoyed learning from the great lawyers at the firm it was always his calling to represent victims of negligence, so he joined McMahan Law, PC to focus his practice exclusively on representing Plaintiffs in personal injury matters. While at McMahan Law, PC Sean’s practice focused on representing victims of elder abuse and medical malpractice. During his time at the firm Sean gained valuable litigation and trial experience—helping the firm’s clients secure more than $40,000, in settlements and awards.