Tadao Okayama was born in the former Japanese part of the island of Sakhalin and worked in the family’s milk delivery business. In 1935, he placed second in the endurance cross country race over 56 km behind non-Olympian Sakuji Okazaki, who was not eligible to compete in the Olympics due to age restrictions. Therefore, Okayama was selected for the Japanese team at the 1936 Winter Olympics to compete in the 50 km cross country race. After World War II, he settled in the Niigata prefecture and worked as a teacher in Myoko. Okayama also served as chairman of the Niigata Prefecture Ski Association. His son Koichiro later became vice chairman of the Ski Association of Japan.