Ayutthaya Province is in Central Thailand.

Ayutthaya (full name Phra Nakhon Si Ayutthaya, Thai: พระนครศรีอยุธยา, IPA: [aˡjutʰajaː]; also spelled "Ayudhya") city is the capital of Ayutthaya province in Thailand. The city was founded in 1350 by King U-Thong, who came here to escape a smallpox outbreak in Lop Buri, and proclaimed it the capital of his kingdom, often referred to as the Ayutthaya kingdom or Siam. Ayutthaya was named after the city of Ayodhya in India, the birthplace of Rama in the Ramayana (Thai, Ramakien). In 1767 the city was destroyed by the Burmese army, and the ruins of the old city now form the Ayutthaya historical park, which is recognized internationally as a UNESCO World Heritage Site. The city was refounded a few kilometers to the east.

The province comprises 16 amphoe:- Ban Phraek; Bang Ban; Bang Pa-in; Bang Pahan; Bang Sai (1404 - บางไทร); Bang Sai (1413 - บางซ้าย); Lat Bua Luang; Maha Rat; Nakhon Luang; Phachi; Phak Hai; Phra Nakhon Si Ayutthaya; Sena; Tha Ruea; Uthai; Wang Noi.