Cosmas P. Diamantis

Cosmas P. Diamantis

Associate Attorney
Cherry Hill, New Jersey

Cosmas P. Diamantis is an associate attorney who practices in several areas including, but not limited to, complex civil litigation, employment and labor, municipal and government, and land use. Cosmas has successfully represented individuals, labor unions, local municipalities, and private corporations before various tribunals including New Jersey State and Federal Courts, the Office of Administrative Law, the Public Employment Relations Commission, various State agencies, and binding arbitrations.

Prior to joining Zeller & Wieliczko, LLP, Cosmas had the honor of serving as a Judicial Law Clerk in the New Jersey Superior Court, Law Division, Civil Part, for Judges Stephen M. Holden, J.S.C. (retired) and Anthony M. Pugliese, J.S.C. (now P.J.Cv.), as well as a Judicial Intern in the New Jersey Superior Court, Appellate Division, for Judge Marie E. Lihotz, P.J.A.D.

During law school, Cosmas was awarded the Marshall Brennan Fellowship, where he studied teaching pedagogy and taught a public high school class four days per week in an urban school district. In addition, he travelled to Vienna, Austria, for an International Moot Court Competition to compete against over 290 law schools from around the world and helped his team to move to advanced rounds. Lastly, as certified legal intern in the Rutgers Children's Justice Clinic, Cosmas successfully argued a motion for a directed verdict that resulted in the dismissal of all charges brought against his juvenile client by the county prosecutor.

When not practicing law, Cosmas is an active member of his community. As a member of the Camden County Bar Association, he frequently volunteers his time to help organize various charitable and fundraising events focused on aiding residents of Camden County. Similarly, as a member of the Order of AHEPA, he helped organize the Philadelphia Greek Independence Day Parade, the regional Hellenic History Tournament, and other fundraising events to raise money for scholarships and other charitable projects.

Year Joined Firm

  • 2013

Areas of Practice

  • Corporate
  • Employment and Labor
  • Land Use, Zoning, and Redevelopment
  • Landlord/Tenant
  • Litigation and Appeals
  • Municipal and Government
  • Municipal Liability
  • Public Schools and Education

Bar Admissions

  • Supreme Court of New Jersey
  • Supreme Court of Pennsylvania
  • U.S. District Court District of New Jersey
  • U.S. Court of Appeals 3rd Circuit


  • Rutgers School of Law - Camden, Camden, New Jersey
    • Juris Doctor - 2012
    • Honors: Dean’s Scholar
    • Honors: Recipient of Dean’s “Pro Bono Publico” Award for Exceptional Service
    • Honors: Fellow, Marshall-Brennan Fellowship
    • Honors: Competitor, Appellate Advocacy: Hunter Moot Court
    • Honors: Teaching Assistant and Competitor, Willem C. Vis International Moot
  • Rutgers University, Camden, New Jersey
    • Bachelor of Arts cum laude - 2009
    • Honors: Alpha Sigma Lambda Honor Society
    • Honors: Teaching Assistant, Ethics and Policy in Criminal Justice
  • Rutgers University, School of Management and Labor Relations, New Brunswick, New Jersey
    • Certificate in Public Sector Labor Relations – expected 2018
  • Rutgers University, School of Business, Camden, New Jersey
    • M.B.A., Master of Business Administration - 2017
    • Honors: President-Elect, Rutgers MBA Association
    • Honors: Secretary, Rutgers MBA Association
    • Honors: Teaching Assistant, Willem C. Vis International Moot Court

Representative Cases

Professional Associations and Memberships

  • Member, Young Lawyers Division, Camden County Bar Association
  • Member, Board of Trustees, Camden County Bar Foundation
  • Member, Young Lawyers Division, New Jersey State Bar Association
  • Order of AHEPA (American Hellenic Education Progressive Association), Member, Camden Chapter / Co-Chair, Young AHEPA Committee
  • Voting Member, Greek American Chamber of Commerce

Past Employment Positions

  • Judicial Law Clerk to the Hon. Anthony M. Pugliese, J.S.C., Superior Court of New Jersey, Camden Vicinage – Civil Division (2013)
  • Judicial Law Clerk to the Hon. Stephen M. Holden, J.S.C., Superior Court of New Jersey, Camden Vicinage – Civil Division (2012-2013)
  • Certified Legal Intern, Rutgers Children’s Justice Clinic (2011-2012)
  • Judicial Intern to the Hon. Marie Lihotz, P.J.A.D. , Superior Court of New Jersey – Appellate Division (2011)
  • Summer Associate, Brown & Connery, LLP (2011)
  • Judicial Intern to the Hon. Stephen M. Holden, J.S.C., Superior Court of New Jersey, Camden Vicinage – Civil Division (2011)
  • Judicial Intern to the Hon. Stephen M. Holden, J.S.C., Superior Court of New Jersey, Camden Vicinage – Criminal Division (2010)


  • Greek