| Sasibongse Prabai | |
| Full Name: | Sasibongse Prabai |
| House: | Chakri dynasty |
| Mother: | Chao Chom Manda Chan |
| Birth Date: | 26 April 1881 |
| Birth Place: | Grand Palace Bangkok, Siam |
| Death Place: | Bangkok, Siam |
Princess Sasibongse Prabai or Phra Chao Boromwongse Ther Phra Ong Chao Sasibongse Prabai (RTGS: Sasiphong Praphai) (Thai: พระเจ้าบรมวงศ์เธอ พระองค์เจ้าศศิพงศ์ประไพ) (26 April 1881 - 31 May 1934), was a Princess of Siam (later Thailand. She was a member of Siamese royal family. She is a daughter of Chulalongkorn, King Rama V of Siam.
Her mother was Chao Chom Manda Chan, daughter of Lord (Phraya) Rajasam Bharakorn. Princess Sasibongse Prabai died on 31 May 1934, at the age of 53.
| Princess Sasibongse Prabai | Father: Chulalongkorn, King Rama V of Siam | Paternal Grandfather: Mongkut, King Rama IV of Siam | Paternal Great-grandfather: Buddha Loetla Nabhalai, King Rama II of Siam |
| Paternal Great-grandmother: Queen Sri Suriyendra | |||
| Paternal Grandmother: Queen Debsirindra | Paternal Great-grandfather: Prince Sirivongse, the Prince Matayabidaksa | ||
| Paternal Great-grandmother: Mom Noi Sirivongs na Ayudhya | |||
| Mother: Chao Chom Manda Chan | Maternal Grandfather: Phraya Rajasam Bharakorn | Maternal Great-grandfather: unknown | |
| Maternal Great-grandmother: unknown | |||
| Maternal Grandmother: unknown | Maternal Great-grandfother: unknown | ||
| Maternal Great-grandmother: unknown |