John F.X. Costello handles primarily serious personal injury matters including wrongful death, medical malpractice, and catastrophic injury. John has been trying personal injury cases in Maryland and Washington, DC for over 30 years and has earned a reputation as a highly effective and personable attorney. As a testament to his dedication and ability, it is common for fellow lawyers and judges to refer cases to John. Throughout his career, John has recovered verdicts and settlements on behalf of injured clients with a combined value over $100 million.

A Washington, DC native, John’s practice has been based in Prince George’s County, Maryland his entire career. He has served as lead counsel in hundreds of jury and non-jury trials. John prides himself on being a tireless advocate on behalf of his clients. The vast majority of John’s cases are referrals from former clients.

John holds an “AV” Preeminent lawyer rating from Martindale Hubbell. He has been selected for inclusion in “Best Lawyers in America” and recognized as a “Top Rated Attorney” in Super Lawyers Magazine.

John is an admitted member of the Bars of Maryland, the District of Columbia, the United States District Court for the District of Maryland, the United States District Court for the District of Columbia, and the United States Court of Appeals for the 4th Circuit.

John graduated from Gonzaga College High School in Washington, D.C. He received both his bachelor’s and law degree from the Catholic University of America.

Professional Affiliations

  • Prince George’s County Bar Association
  • Montgomery County Bar Association
  • District of Columbia Bar Association
  • Maryland State Bar Association