Trang or Muang Thap Thiang used to be a port involved in foreign trade. It was the first city where rubber was planted. Phraya Ratsadanupradit Mahison Phakdi brought rubber from Malaysia and planted it here before anywhere else in southern Thailand in 1899. Rubber is now considered an important commodity of Thailand. The important Trang River flows through the province from its origin in the Khao Luang mountain range and the Palian River from the Banthat mountain range.

Trang is a coastal province on the Indian Ocean with a long western coastline of about 199 kilometres. The province consists of an archipelago in the Andaman Sea with over 46 islands. Of these, 12 are in Amphoe Kantang, 13 in Amphoe Palian and 21 in Amphoe Sikao. The best time for sea travel is during October to May of the following year.

Trang has a total area of 4,941 square kilometres and is divided into 9 districts (Amphoe) and 1 sub-district (King Amphoe); Amphoe Kantang, Amphoe Huai Yot, Amphoe Yan Ta Khao, Amphoe Palian, Amphoe Sikao, Amphoe Wang Wiset, Amphoe Na Yong, Amphoe Ratsada, and King Amphoe Hat Samran.