The library uses a classical temple form with a pedimented central entrance flanked by recessed wings. The distyle in antis portico shelters double doors. The Clarion Women's Club established the Clarion Free Library Association in 1914, naming it originally for Mary Ann Ross, president of the club, and her son John D. Ross, who funded its building in 1920. Oil City architect Emmet E. Bailey (1872–1942), who designed many institutional buildings and churches in the region, designed the original north wing. An addition in 1986–1987 to the south elevation added stacks and reading rooms.