The Front Palace, officially the Phraratchawang Bowon Sathanmongkhon (พระราชวังบวรสถานมงคล), was the residence of the royal holder of the same title during the early-to-mid Rattanakosin Kingdom. The palace was built at the same time as the Grand Palace, following the accession of King Rama I and the foundation of Rattanakosin as the capital city in 1782. It was located at the northern end of the inner fortified city, directly in front of the Grand Palace, where the king lived, and provided security to the city.

Krom Phra Ratchawang Bowon Sathan Mongkhon กรมพระราชวังบวรสถานมงคล, colloquially known as the Front Palace, was the title of the uparaja of Siam, variously translated as "viceroy", "vice king" or "Lord/Prince of the Front Palace", as the titleholder resided in the physical residence of the same name. The office of Front Palace was considered second only to the king and regarded as the heir presumptive. The name, with its dual meaning, originated in the Ayutthaya period, and the holder later gained significant powers during the Rattanakosin period. Front Palace occupants were usually a son or brother of the reigning monarch. The office existed until the death of the last occupant, Prince Vichaichan, in 1885. King Chulalongkorn then abolished the office of an heir presumptive, introducing in its stead the Western concept of a crown prince as heir apparent, and styled the new office "Crown Prince of Siam".