Rex Allen, Jr. (born August 23, 1947) is an American country music singer, who started singing at the age of six; he had followed in the footsteps of his father, Rex Allen, a singing cowboy and the narrator of many Walt Disney films. Rex Allen, Jr. followed his father's footsteps as a film narrator when he lent his voice as narrator of the Jim Carrey movie, Me, Myself, and Irene.

Allen was born in Chicago, Illinois. Singing in the "countrypolitan" style, he had hits with "Goodbye" (1974), "I'm Gettin Good At Missing You (Solitaire)" (1977), "Lonely Street" (1977), "Two Less Lonely People" (1977), "With Love" (1978), "If I Fell in Love With You" (1979), "It's Over" (1980), "Drink it Down, Lady" (1980), "Cup of Tea" (1980, a duet with Margo Smith) and others. He is also the composer and performer of the alternate state anthem of Arizona, entitled "Arizona".

Rex Jr. was a regular on The Statler Brothers Show on The Nashville Network in the 1990s, and he hosted the spin-off series, Yesteryear.