The Ministry of the Privy Seal (Thai: กระทรวงมุรธาธร, RTGS: Krasuang Murathathon) was a government ministry of Siam (Thailand) in existence from 1892 to 1896 and again from 1911 to 1926. Originating from the historical Royal Scribes Department (กรมพระอาลักษณ์, Krom Phra Alak), it was responsible for royal secretarial and document and record-keeping matters.