Yukio Kasaya (笠谷 幸生 Kasaya Yukio, born August 17, 1943 in Yoichi, Hokkaido) is a Japanese former ski jumper. He was one of the most successful ski jumpers of the late 1960s and the early 1970s. At the 1970 FIS Nordic World Ski Championships at Vysoké Tatry, Czechoslovakia, he finished second in the individual normal hill behind Gariy Napalkov (Soviet Union). At the 1971/72 Four Hills Tournament, he won the first three jumping events and would probably have won the overall combined tournament. However, before jumping in the last event at Bischofshofen, he returned to Japan in order to prepare for the 1972 Winter Olympics, which took place in Sapporo. There he won the gold medal in the individual normal hill, where Japan won all three medals. In 1972 the Olympic Games also doubled as the FIS Nordic World Ski Championships, so Kasaya's gold medal victory in the individual normal hill made him world champion as well.
As Japan's first ever Winter Olympic gold medalist, Kasaya is a national hero.