Rathfarnham or Rathfarnam (Irish: Ráth Fearnáin, meaning "Fearnán's ringfort") is a Southside suburb of Dublin, Ireland. It is south of Terenure, east of Templeogue, and is in the postal districts of Dublin 14 and 16. It is within the administrative areas of both Dún Laoghaire-Rathdown and South Dublin County Councils.