Irene May Guest (July 22, 1900 – June 14, 1970), also known by her married name Irene Loog, was an American competition swimmer, Olympic champion, and world record-holder. She represented the United States as a 19-year-old at the 1920 Summer Olympics in Antwerp, Belgium, where she received a pair of medals. Guest received her first medal in the women's 100-meter freestyle in which she finished second behind fellow American Ethelda Bleibtrey, earning a silver medal with a time of 1:17.0. In the women's 4×100 metres freestyle relay, she won a gold medal with U.S. teammates Bleibtrey, Frances Schroth and Margaret Woodbridge in a new world-record time of 5:11.6. Guest was inducted into the International Swimming Hall of Fame as an "honor pioneer swimmer" in 1990.