The 1966 U.S. Women's Open was the 21st U.S. Women's Open, held June 30 to July 3 at Hazeltine National Golf Club in Chaska, Minnesota, a suburb southwest of Minneapolis. Sandra Spuzich, age 29, won her only major title, a stroke ahead of runner-up Carol Mann, the defending champion. A stroke back in third was four-time champion Mickey Wright. Spuzich was the 54-hole leader by a stroke over the two former champions and played in the final pair with Mann. It was the first of seven victories on the LPGA Tour for Spuzich.