Princess Bismai Bimalasataya or Phra Chao Boromwongse Ther Phra Ong Chao Bismai Bimalasataya (RTGS: Phitsamai Phimonsat) (Thai: พระเจ้าบรมวงศ์เธอ พระองค์เจ้าพิสมัยพิมลสัตย์) (20 December 1881 – 6 February 1936) was the Princess of Siam (later Thailand). She was a member of Siamese Royal Family. She was a daughter of Chulalongkorn, King Rama V of Siam and Chao Chom Manda Ruen.
She died on 6 February 1936, at the age of 54.
Honours
Dame Grand Commander (Second Class, upper grade) of the Most Illustrious Order of Chula Chom Klao (1899)
King Rama V Royal Cypher Medal, 2nd Class (1908)
King Rama VI Royal Cypher Medal, 2nd Class (1912)
King Rama VII Royal Cypher Medal, 2nd Class (1926)