Sa Kaeo Province, named after the ancient twin reservoirs "Sa Kaeo" and "Sa Khwan" located in its central district, has a rich history dating back to the late 18th century. In 1782, during the Thonburi period, the future King Rama I, then a military leader, halted his army near these pools on a campaign in Cambodia. The reservoirs provided essential resources for his troops, and the waters, deemed sacred, were later used in royal oaths of allegiance.

Originally, Sa Kaeo served as a checkpoint for the movement of goods and people, governed by local officials overseeing trade and security. In 1909, the area was elevated to a minor district, "King Amphoe Sa Kaeo," under Kabin Buri District, and later recognized as a full district within Prachinburi Province. In 1993, a royal decree officially established Sa Kaeo as Thailand’s 74th province, with administrative functions commencing on December 1 of that year.