Maha Vajirunhis, Crown Prince of Siam (Thai: ????????????; RTGS: Maha Wachirunnahit; 27 June 1878 – 4 January 1895) was the first Crown Prince of the Chakri dynasty.
He was the first son of King Chulalongkorn and Queen Savang Vadhana together, who were half-siblings.
The King built a palace for the Prince, nicknamed Windsor Palace.
The European-style palace was demolished after his death.
The site is now occupied by the National Stadium of Thailand.