John Fahy (8 June 1893 – 19 July 1969) was an Irish priest, republican, agrarian and radical. He is perhaps best known for creating the political party Lia Fáil, a radical agrarian movement and newspaper in which Fahy expressed republican views. Lia Fáil made national headlines in the early 1960s after some members were arrested for rural agitation but later escaped jail and went on the run, and Fahy aided and abetted them.