The Phya Thai Palace (Thai: วังพญาไท Wang Phaya Thai) or Royal Phya Thai Palace (พระราชวังพญาไท Phra Ratchawang Phaya Thai) is located on the banks of the Samsen Canal (คลองสามเสน Khlong Samsen) on Rajavithee Road (ถนนราชวิถี Thanon Ratchawithi) in the Ratchathewi district of Bangkok. King Rama V bestowed on it the royal name of the Royal Residence of the Phya Thai (พระตำหนักพญาไท Phra Tamnak Phaya Thai) or the Phya Thai Palace, with Phya Thai (พญาไท Phaya Thai) meaning Lord of the Thais, during his reign and so it was built with this bearing on design.

The construction of Phya Thai Palace began in 1909. It was built at Rama V's behest so that he might stay there and look out over the farms, plantations and livestock in the area. The palace grounds included those areas directly opposite the palace. He also had a complex included in the compound where the Royal Ploughing Ceremony might take place, since used on many occasions.

The Phya Thai Palace was only used by King Rama V for a short time as he died several months after the crowning of the new king.