Pablo Beltrán Ruiz (born 5 March 1915 in Los Mochis, Sinaloa, Mexico - died 29 July 2008) was a Mexican composer and bandleader, most famous for composing the song "¿Quién será?", a Spanish-language hit that, with English lyrics by Norman Gimbel, was made famous internationally by Dean Martin as "Sway" in 1954, and by Bobby Rydell in 1960. Other songs by Beltràn include "Picnic a Go-Go" (1966) and "La Sombra de tu Sonrisa" (1966), an instrumental version of "The Shadow of Your Smile".