Justice John C. Arnold was born on March 10, 1887, in Curwensville, Clearfield County. He attended public schools and went on to receive an LL.B. from the University of Pennsylvania in 1909. He began his career by serving as solicitor of DuBois Borough. Justice Arnold resigned from this position in 1925 to join private practice.
Justice Arnold became a partner at the firm of Arnold & Chaplin. He remained in private practice until his appointment to the Superior Court in 1945. He served in this capacity until he was elected Justice of the Supreme Court of Pennsylvania in 1953. Justice Arnold passed away in 1958.
During his career, Justice Arnold held several prestigious memberships and positions: president of the Clearfield County Bar Association, president of the Pennsylvania Bar Association, member of the American Judicature Society, member of the Sociolegal Club of Philadelphia, member of the Board of Governance of the Supreme Court, member of the Board of Managers of the Law Alumni Society of the University of Pennsylvania, and trustee of Dickinson University and Dickinson School of Law.