Lunca de Jos is a commune located in Harghita County within the Transylvania region of Romania. It is situated in the ethno-cultural region known as Székely Land.
The commune is composed of nine distinct villages: Barațcoș (Barackospatak), Lunca de Jos, Puntea Lupului (Farkaspalló), Poiana Fagului (Bükkhavaspataka), Valea Boroș (Borospataka), Valea Capelei (Kápolnáspataka), Valea Întunecoasă (Sötétpataka), Valea lui Antaloc (Antalokpataka), and Valea Rece (Hidegség).