Shigeo Arai (新井 茂雄 Arai Shigeo, born August 8, 1916, Shizuoka – July 19, 1944, Burma) was a Japanese freestyle swimmer. He won the gold medal for the Men's 4×200 m freestyle relay and a bronze medal for the 100 m freestyle in the 1936 Summer Olympics.
While serving in the Imperial Japanese Army during World War II, he was killed in action in Burma on July 18, 1944.
- 1936 Olympics 100 m freestyle - 58.0
- 1936 Olympics 4×200 m freestyle relay - 8:51.5 (World record)