"Quién" (English: "Who") is a latin pop song by Guatemalan recording artist Ricardo Arjona, released on 19 June 2007 as the lead single from his compilation album, Quién Dijo Ayer (2007). The song's lyrics were written by Arjona, and its music was composed by Puerto Rican singer-songwriter Tommy Torres, who also worked with Arjona on his tenth studio album, Adentro (2005). Performed with additional background vocals by Torres, "Quien" was produced by Arjona with longtime collaborators Dan Warner and Lee Levin under their stage name Los Gringos, and was recorded between several studios in Miami and Mexico City.