"If This World Were Mine" is a 1967 song by soul duo Marvin Gaye and Tammi Terrell from their album United. Written solely by Gaye, it was one of the few songs they recorded without Ashford & Simpson writing or producing. When it was released as a single in November 1967 as the B-side to the duo's "If I Could Build My Whole World Around You", it hit the Billboard pop singles chart, peaking at number 68, and peaked at number 27 on the Billboard R&B singles chart. Gaye would later put the song into his set list during his last tours in the early 1980s as he performed a medley of his hits with Terrell.