Listen to Who Let the Dogs Out? (From "The Hangover") online. Who Let the Dogs Out? (From "The Hangover") is an Unknown language song and is sung by Movie Soundtrack All Stars. Who Let the Dogs Out? (From "The Hangover"), from the album Wolfpack Moments - Songs from the Hangover Movies, was released in the year 2014. The duration of the song is 3:19. Download Unknown songs online from JioSaavn.