Cathy Jean Ferguson, known for a time by her married name Cathy Ferguson Brennan is an American former competition swimmer, who competed for the Los Angeles Athletic Club, was a two-time Olympic gold medalist, and a former world record-holder. She participated at the 1964 Olympic Games in Tokyo, Japan, where she received the gold medal for winning the women's 100-meter backstroke, and another gold as a member of the first-place U.S. team in the women's 4×100-meter medley relay. After completing a Doctorate from the U.S. International University in San Diego, she worked as a Professor, Coach and Director of Aquatics at California State University, Long Beach for 20 years, was a director of Sports Medicine at Anaheim Memorial Hospital, and served as a CEO for Girl Scouts of Central California.