Sheena Barthelus is an Associate with Mark’s O’Neill, O’Brien, Doherty & Kelly. She is admitted to practice in New York. Sheena graduated from Syracuse University in 2014, with a bachelor’s degree in Political Science and English and Textual Studies. She attended Benjamin N. Cardozo School of Law, graduating in 2019. There, she served on the Cardozo Journal of Conflict Resolution as a staff editor and participated in organizations such as the Black Law Students Association and Business Law Society.

During law school, Sheena interned for the United States Department of Labor, Employee Benefits Security Administration. She investigated violations of ERISA and provided guidance on employer-sponsored retirement benefits and health benefit plans. Additionally, she served as a judicial extern for the Honorable Devin P. Cohen, New York Supreme Court, 2nd Judicial District. Subsequently, she provided legal and regulatory support as a Law Clerk for Lloyd’s America Inc.

Prior to joining Marks O’Neill, Sheena was employed at the Brain Injury Rights Group where she provided legal assistance to families with traumatic brain injuries and other disabilities.

During her spare time, she enjoys reading, traveling and biking.

Sheena Barthelus

Phone 646-454-4878

Sheena Barthelus PDF


  • J.D. Benjamin N. Cardozo School of Law, 2019
  • B.A., Syracuse University 2014

Bar Admissions

  • New York

Bar Associations

Practice Areas

  • Casualty Group
  • Professional Liability

Representative Cases