Chanthaburi (; Chong: จันกะบูย; ; "Moon City") is a province (changwat) of Thailand. It is in the east of Thailand, on the border with Battambang and Pailin of Cambodia and on the shore of the Gulf of Thailand. Neighbouring provinces are Trat in the east and Rayong, Chonburi, Chachoengsao, and Sa Kaeo to the west and north.