Princess Izumi (泉皇女 Izumi no himemiko?) (died 734) was a person in Japan during the Asuka period and the Nara period. She was a daughter of Emperor Tenji. Her mother was Lady Shikobuko, whose father was Oshimi no Miyakko Otatsu. She had an elder brother, Prince Kawashima, and an elder sister, Princess Ōe.
Although her sister, Princess Ōe, and other half-sisters were married to Emperor Tenmu or his sons, Izumi did not marry because she was too young. When she reached the age suitable for marriage, she could not marry, because there were no appropriate men among Emperor Tenmu's sons.
In addition to that condition, her brother Prince Kawashima betrayed Prince Ōtsu and his followers, and they were all punished. Because of that, Prince Kawashima and his relatives became the targets of criticism. After Prince Kawashima and Princess Ōe died several years later, she was completely isolated.
She was selected by divination as the Saiō in 701 when she was in her thirties, because the Saio of that year, Princess Taki, was suddenly dismissed. In principle, a newly selected Saio was supposed to make preparation by staying in the Abstinence-house near the capital for two years prior to going to Ise. However, she was in the Abstinence-house for over five years from 701 to 706. Also, she stayed in the Saikū in Ise for only half a year and was made to retire from the post. These unprecedented cases might be because of some political intentions.
She was almost 40 years old when she returned to the capital. She could not marry anyone as she became too old, and lived an unmarried life until she died in 734, in her sixties.