[5] The province also serves as a major center for fruit growing, gem mining and fishing in the region.

[6] Trat is believed to be a corruption of "Krat"(กราด) the Thai name for the tree Dipterocarpus intricatus, common to the region and used to make brooms.

[8][9][10] In 1408, Chinese writer and voyager Ma Huan made one of the earliest references to the gems found in modern-day Chanthaburi and Trat provinces.

[11] The history of Trat can be traced back to the early 17th century during the reign of King Prasat Thong of the Ayutthaya Kingdom.

Formerly known as Mueang Thung Yai, Trat has played an important role in the development of the country's stability and economy due to its strategic location.

Beginning in the 1850s a gem rush began in modern-day Chanthaburi, Trat and Pailin provinces, resulting in an influx of immigrants from Burma who became the Kula people.

[15] On 23 March 1907, it was agreed between Siam and France that France would return control of Trat, except Koh Kong, to the Siamese in exchange for the provinces of Phra Tabong (Battambang), Siem Reap, and Serei Sophoan which all had a Khmer majority population as part of the 1907 Franco-Siamese Treaty.

When the Vietnamese pushed the Khmer Rouge out of Cambodia in 1985, Pol Pot fled to Thailand and made his headquarters in a plantation villa near Trat.

[27] In order to better provide for themselves and their families, some farmers shifted away from monoculture farming towards orchard tourism, a form of agritourism.

[28] Historically both Trat and Chanthaburi provinces were Thailand's principal area for ruby production, alongside being a major source of sapphires.

The region had started becoming a major source of the world's rubies and sapphires supply in the late 1800s, however it lagged behind the Burmese gem industry.

By 1982, an estimated 70% of the world's high-quality rubies originated from Thailand, of which 85% to 90% came from the Chanthaburi-Trat region, although Burma still led in quality.

Since the end of the orogeny, the region became geologically quiet, with the tropical climate resulting in intense weathering and erosion.

As of 26 November 2019 there are:[32] one Trat Provincial Administration Organisation (ongkan borihan suan changwat) and 14 municipal (thesaban) areas in the province.

The non-municipal areas are administered by 29 Subdistrict Administrative Organisations – SAO (ongkan borihan suan tambon).