Praphalsai "Waen" Minpraphal (Thai: ประพาฬสาย มินประพาฬ; born January 7, 1978) is a Thai former swimmer, who specialized in butterfly, but also competed in backstroke and individual medley. She represented Thailand in all three editions of the Olympic Games since 1992, and earned numerous medals in her own specialties at the Southeast Asian Games since 1991. While residing in the United States on her college career, she helped the California Golden Bears set a new world record (1:49.23) and capture the 4×50 m medley title at the 2000 NCAA Women's Swimming and Diving Championships. Minpraphal is among the Asian swimmers, along with Joscelin Yeo of Singapore and Akiko Thomson of the Philippines, to train for the Bears under women's head coach Teri McKeever.