Osborne was born in Providence, Rhode Island. He is the youngest of 12 children and is part of a musical family. He has five brothers and six sisters, some of whom went on to have music careers (his brother Billy was an L.T.D. bandmate). Osborne's father, Clarence "Legs" Osborne, was a popular trumpeter who played with Lionel Hampton, Count Basie, and Duke Ellington and died when Osborne was thirteen. Osborne started his music career in 1970 with a band called Love Men Ltd., who would later become known as L.T.D.