The village is named for St. Srafán, whose feast day in the Martyrology of Tallaght was 23 May. Straffan was also one of 300 Irish locations accorded its own place-legend in Dinnshenchas Érenn (Metrical (ed. Edward Gwynn 1924) iv, pp328–331). It consisted of a poem called "Lumman Tige Srafain", about a warrior named Lumann who possessed a wonderful shield and who, according to the poem, died of his wounds at Tech Srafáin. Two forms of the name cited in the tale, "Tech Srafáin" and "Tige Srafáin", are Middle Irish nominative and genitive case forms. The spelling Strafáin is unusual. "Straphan" or "Straffan" is a shortened Anglicised form of the original Irish "Teach Srafáin" (the initial Str- is the usual development of Irish Sr in English).