Rosemary "Rosie" Casals (born September 16, 1948) is an American former professional tennis player. Casals earned her reputation as a rebel in the tennis world when she began competing in the early 1960s. During a tennis career that spanned more than two decades, she won more than 90 titles and was crucial to many of the changes in women's tennis during the 1960s and 1970s.