Alethea Boon is an athlete from New Zealand. She represented New Zealand in artistic gymnastics at the 1998 Commonwealth Games and the 2002 Commonwealth Games, and in weightlifting at the 2018 Commonwealth Games. Boon was born in Suva, Fiji, and grew up in Auckland, New Zealand. She competed in artistic gymnastics, attending two Commonwealth Games, and studied exercise science at Brigham Young University while continuing to compete while at university. She retired at the age of 24.