Map - Thurso

Thurso ( pronounced ; Thursa, Inbhir Theòrsa ) is a town and former burgh on the north coast of the Highland council area of Scotland. Situated in the historical County of Caithness, it is the northernmost town on the island of Great Britain. From a latitudal standpoint, Thurso is located further north than the southernmost point of Norway and in addition lies more than 500 mi north of London.

It lies at the junction of the north–south A9 road and the west–east A836 road, connected to Bridge of Forss in the west and Castletown in the east. The 34 mi River Thurso flows through the town and into Thurso Bay and the Pentland Firth. The river estuary serves as a small harbour. At the 2011 Census, Thurso had a population of 7,933. The larger Thurso civil parish including the town and the surrounding countryside had a population of 9,112.

Thurso functioned as an important Norse port, and later traded with ports throughout northern Europe until the 19th century. A thriving fishing centre, Thurso also had a reputation for its linen-cloth and tanning activities. , the Dounreay Nuclear Research Establishment, although mostly decommissioned at the end of the 20th century, employs a significant number of the local population. The Category-A listed ruined Old St Peter's Church (St. Peter's Kirk) is one of the oldest churches in Scotland, dating to at least 1125. The current church, St Andrew's and St Peter's, was built in 1832 to a design by William Burn in the Gothic style.

The town contains the main campus of North Highland College and Thurso High School, the northernmost secondary school on the British mainland, which was established in 1958. Thurso Castle, built in 1872, is in ruins. Thurso is home to the football team Thurso FC, established in 1998, who play in the North Caledonian League, and the rugby teams Caithness Crushers and Caithness RFC.

Thurso railway station, opened in 1874, was the most northern station on the Sutherland and Caithness Railway. The nearby port of Scrabster provides ferry services to the Orkney Islands; the Northlink ferry (MV Hamnavoe) operates between Scrabster and Stromness.

Originally Thurso was known by the Celtic name of tarvodubron meaning "bull water" or "bull river"; similarly Dunnet Head was tarvedunum standing for "bull fort" and the name of the town name may have its roots there. Norse influence translated its name to Thjorsá, then altered it to Thorsá, based on the deity of Thor and translating as (the place on) Thor's River.

The local Scots name, Thursa, derives from the Norse, as does the modern Scottish Gaelic Inbhir Theòrsa. means a river mouth, and is generally found as Inver in many anglicised names.