Surat, previously known as Suryapur, is a commercial city of the Indian state of Gujarat. It is also administrative capital of Surat district and one of the fastest growing cities in India. The city proper is the third cleanest city in India. Surat is Gujarat's second largest city and India's 8th most populated city (in terms of Population in Municipal Corporation area of the City) with a population of 4.5 million. Surat ranks fourth in a global study of fastest developing cities conducted by The City Mayors Foundation, an international think tank on urban affairs. It is the fastest growing Indian city in terms of economic prosperity. The city registered an annualised GDP growth rate of 11.5 per cent over the seven fiscal years between 2001 and 2008, according to data compiled by the economic research firm Indicus Analytics. UK-based charity, The Ecological Sequestration Trust (TEST), has selected Surat as one of the three cities in the world, to be developed as "global cities."

The city is located 306 km south of state capital Gandhinagar, and is situated on the left bank of the Tapti River (Tapi), the centre being around 22 km (14 mi) from its mouth. A moat divides the older parts of the city, with its narrow streets and handsome houses, and the newer suburbs. The city is largely recognised for its textile and diamond businesses. It is also known as the diamond capital of the world and the textile capital/Manchester textile city of India, a distinction it took over from Ahmedabad. It is also known as the "Embroidery capital of India" with the highest number of embroidery machines than any other city. 92% of the world's diamonds are cut and polished in Surat. It has one of the highest GDP growth rates in India at 11.5% as of 2008. Surat was the primary port of India during the Mughal period, a distinction it lost to Bombay during the late 17th century as the East India Company grew.

Surat Thani (often in short Surat, Thai: สุราษฎร์ธานี) former name Chaiya Province is the largest of the southern provinces (changwat) of Thailand, on the eastern shore of the Gulf of Thailand. Surat Thani means City of Good People, the title given to the city by King Vajiravudh (Rama VI).

The area of Surat Thani was already inhabited in prehistoric times by Semang and Malayan tribes. Founded in the 3rd century, until the 13th century the Srivijaya kingdom dominated the Malay Peninsula. The city Chaiya contains several ruins from Srivijaya times, and was probably a regional capital of the kingdom. Some Thai historians even claim that it was the capital of the kingdom itself for some time, but this is generally disputed. Wiang Sa was another main settlement of that time.

After the fall of the Srivijaya it was divided into the cities (Mueang) Chaiya, Thatong (now Kanchanadit) and Khirirat Nikhom. While Chaiya was administrated directly from the capital, Thatong and Khirirat were controlled by the Nakhon Si Thammarat kingdom. In 1899 they were merged into one province named Chaiya. In 1915 also the court of the Monthon Chumphon was moved to Bandon, which received its new name Surat Thani on July 29, 1915 during a visit of King Vajiravudh (Rama VI). The monthon was renamed to Surat accordingly. In 1926 it was abolished and incorporated into monthon Nakhon Si Thammarat. In 1933 the monthon was dissolved, so the province became the first level administrative subdivision.