Wat Thammikarat, originally known as Wat Mukraj, was a royal temple during the Ayutthaya period. It is located in the Phra Nakhon Si Ayutthaya District of Phra Nakhon Si Ayutthaya Province, adjacent to the ancient palace and Wat Phra Si Sanphet. Wat Thammikarat was built by Phaya Thammikarat, the son of King Sai Nam Phueng, leading to the assumption that it was established before the founding of Ayutthaya. Initially named Wat Mukraj, it was later renamed in honor of its creator, becoming Wat Thammikarat.