Samantha Jane Stosur (/ˈstoʊsər/ STOH-sər; born 30 March 1984) is an Australian professional tennis player. She is a former world No. 1 in doubles, a ranking which she held for 61 weeks, and a former world No. 4 in singles. She was also the top-ranked Australian singles player for 452 consecutive weeks, from October 2008 to June 2017. She has won a combined total of 38 titles on the WTA Tour: nine in singles, 26 in doubles and three in mixed doubles, as well as amassing over $18 million in prize money.