Ramrachathirat (Thai: รามราชาธิราช) was a king of Ayutthaya, an ancient kingdom in Thailand.
A son of Ramesuan and member of the House of Uthong, he succeeded his father to the throne of Ayutthaya in 757 LE (1938 BE, 1395/96 CE). He reigned until 771 LE (1952 BE, 1409/10 CE) when he was deposed in a coup by Inracha, his relative from the House of Suphannaphum. This coup marked the end of Uthong and the rise of Suphannaphum, which would rule over Ayutthaya for almost two hundred years.
Historical sources vary in relation to the fate of the dethroned monarch. Some say he was banished. Some say he was executed.