"Who's That Girl" is an up-tempo electro R&B song performed by Australian singer-songwriter Guy Sebastian which features American rapper Eve. It was written by Sebastian, with Eve writing and performing the rap. Sebastian co-produced the song with Andre Harris. Released as a digital download on 5 November 2010, it was the only single released in Australia from Sebastian's retrospective album Twenty Ten. "Who's That Girl" reached number one on the ARIA Singles Chart, Sebastian's fifth of six number one singles in Australia and Eve's first. It was also Sebastian's seventh of 12 top ten singles on the Australian charts. It reached 5× platinum certification in 2014.