Judge David Hammer was elected in May 2018 to fill an unexpired judicial term and re-elected in May 2024. He served as the Supervising Judge of Jefferson County until January 1, 2025, when he became the Chief Judge of the new Twenty-Eighth Judicial Circuit (Jefferson County).

Judge Hammer is one of seven judges on the West Virginia Business Court, presiding over complex business disputes throughout West Virginia. He also supervises the Jefferson County Adult Treatment Court; he and a treatment team meet weekly with people to address their substance use disorders and recovery. He has sat by temporary assignment on the Supreme Court of Appeals of West Virginia in place of a justice who was recused from a case.

As a lawyer and then a judge, he has been a presenter at legal symposia on employment, class action, and evidentiary topics.

He is a 1985 graduate of Temple University and a 1988 graduate of the College of William & Mary, Marshall Wythe School of Law.

He co-founded Hammer, Ferretti & Schiavoni in 1992 and continued to work there until his election in 2018. He concentrated his practice primarily in employment law, wage and hour, and municipal law.

He has served as President of the West Virginia Employment Lawyers and as President of the West Virginia Association of Justice. He also served as chair of the Amicus Curiae Committees of both organizations. He is a co-drafter of the West Virginia Voluntary Farmland Protection Act and was appointed by then-Governor Earl Ray Tomblin to serve on the West Virginia Agricultural Land Protection Authority. He currently serves as a statutory representative on the West Virginia Investment Management Board.

He and his wife, Effie, live in Shepherdstown and have two daughters and a son.