The Adelphikos (spelled αδελφικός) fraternity, formed in 1913, is a Grove City College (Pennsylvania, United States) social fraternity that originally consisted of 10 members. Adelphikos was the first official fraternity on campus, and the first to use Greek letters. The fraternity began struggling in the late 1970s, committing violations of campus rules which resulted in the loss of college recognition during the 1990s. In 2000, the fraternity was re-established as a Christian brotherhood.