Sunthorn Phu was born in the fifth year of the reign of King Rama I. His father was a native of Muang Klaeng, a township in the province of Rayong, but his married life was spent in Bangkok. Soon after young Phu was born, his parents divorced. His father went back to Muang Klaeng and took holy orders there. His mother married again and later became the wet-nurse of a princess in the royal palace. Young Phu stayed with his mother and thus spent his early years in the palace.