Mark Greaney (born 23 June 1980) is an Irish musician. He is best known as the singer and guitarist in the alternative rock band JJ72, which he fronted from 1996 until 2006. He was later the frontman of Concerto for Constantine and describes himself as "the perpetual writer of a solo record". Greaney is currently a tutor at the Dublin campus of the Brighton Institute of Modern Music.