The origin of the place name Cill Flainn is unknown. Two suggestions are commonly circulated. ‘Cill’ in Irish can mean 'cell' or 'churchyard' so in context might mean 'church of Flainn.' A popularised tale is that it was named after a Roman Catholic hermit monk, Flainn, said to have lived by the River Shannow (which runs through Kilflynn). Crippled and blind, he was visited by the Virgin Mary, who offered to restore his ailing sight. Flainn declined, asking for the miraculous power to be transferred to others via a local well (now Tobar Flainn, well or spring of Flainn). Some refer to this person as ‘St Flainn,’ but no such person was canonised. There is possible confusion with St Flannan, originally from Killaloe in County Clare.