Smiley began his career as a child actor playing the title role in "Oliver!" in 1965 on Broadway. In 1974 Smiley was given a $200,000 advance and recorded an album "Breathlessly Brett" managed and produced by Rolling Stones manager Andrew Loog Oldham with Steve Marriott from the Small Faces and Humble Pie on guitar. After the single "Va Va Voom" did not chart the album was the album was shelved and remained unreleased until 2004.
In 1977 Smiley starred as role of Prince in the American erotic musical comedy "Cinderella" and had an appearance in Paul Schraders "American Gigolo". After recovered from the drug excesses of his past, Smiley continued to record and perform mostly around New York City until 2015. Brett Smiley died on January 8, 2016 after a lengthy battle with HIV and hepatitis.