"What You Won't Do for Love" is a song by American singer-songwriter Bobby Caldwell. It was released in September 1978 as the lead single from his eponymous debut album (1978). It was written by Caldwell and Alfons Kettner, and produced by Ann Holloway. The song has been covered and sampled numerous times, including by Tupac Shakur in the posthumous 1998 hit "Do for Love".

Robert Hunter Caldwell was an American singer, songwriter, and musician. He released several albums spanning R&B, soul, jazz, and adult contemporary. He is known for his soulful and versatile vocals. Caldwell released the hit single and his signature song "What You Won't Do for Love" from his double platinum debut album Bobby Caldwell in 1978. After several R&B and smooth jazz albums, Caldwell turned to singing standards from the Great American Songbook. He wrote many songs for other artists, including the Billboard Hot 100 No. 1 single "The Next Time I Fall" for Amy Grant and Peter Cetera. Caldwell's musical catalog is perhaps best known today for its later sampling by several prolific hip hop and R&B artists.