On This Day August 22, 1987, Madonna's infectious single “Who’s That Girl” became the #1 song in America, holding the top spot from August 22 to August 28. This track wasn’t just a hit in the U.S.—it also reached #1 in the UK, Canada, Italy, the Netherlands, Belgium, Ireland, Denmark, and Israel. “Who’s That Girl” showcased Madonna’s global appeal and her ability to dominate the charts worldwide, making it one of the defining songs of the late 80s.