Stacy Lewis (born February 16, 1985) is an American professional golfer on the U.S.-based LPGA Tour. She defeated Ai Miyazato at the 2013 RR Donnelley LPGA Founders Cup in Arizona to become the #1 ranked women's golfer in the world.

Born in Toledo, Ohio, Lewis grew up in Texas and went to college in Arkansas majoring in finance and accounting. She was a decorated amateur and a four-time All-American at the University of Arkansas. As a redshirt freshman in 2005, she won the Southeastern Conference Tournament and was named SEC Freshman Golfer of the Year. In 2006, she won the Women's Western Amateur. Lewis finished first in the 2007 LPGA NW Arkansas Championship, a professional LPGA tournament that was shortened to one round and Lewis's win was declared unofficial.

In her senior season in 2008, Lewis again won the SEC Tournament and was selected SEC Golfer of the Year and SEC Golf Scholar Athlete of the Year. She was named to the ESPN the Magazine Academic All-America team for the second time and NGCA All-America for the fourth time. As a member of U.S. Curtis Cup team in 2008, Lewis became the first player ever to go 5–0 in a single Curtis Cup.

Following the Curtis Cup victory, Lewis turned professional and won her first official professional tournament at the 2011 Kraft Nabisco Championship by defeating the former world number 1 and defending champion Yani Tseng. In the 2012 season, Lewis won five tournaments, and became the first American player to win the LPGA Player of the Year award since Beth Daniel in 1994.