Tory Island, or simply Tory, is an island 14.5 kilometres (7+3⁄4 nautical miles) off the north-west coast of County Donegal in the north-west of Ulster, the northern province in Ireland. It is officially known by its Irish name Toraigh, which, although spelled thus, is pronounced the same as the English version. It is the most remote inhabited island of Ireland. The name toraigh means "place of steep rocky heights".

The main spoken language on the island is Irish, although English is spoken as well, to communicate with visitors. Tory is part of the Donegal Gaeltacht, and Ulster Irish (Gaeilge Uladh) is the main Irish dialect in use.

The island is approximately five kilometres (three miles) long and 1 kilometre (0.6 miles) wide, with an area of 3.581 km (885 acres). The 2022 census recorded a population of 141, an increase from the 2016 population of 119. The population is distributed among four towns: An Baile Thoir (East Town), An Baile Thiar (West Town), An Lár (Middletown) and Úrbaile (Newtown). Petrol and diesel are available from Tory Oil at prices significantly higher than on the mainland.

Tory has no airport, but it has regular ferry connections from mainland County Donegal. The ferry operates daily all year round. It does not take cars, but holds up to 70 passengers. During the winter months, ferry crossings may not be possible on some days due to rough seas. However, between November and March a four-seater helicopter operates every other Thursday between Falcarragh and Tory.

Power on the island is generated by three diesel electricity generators. These have a total capacity of 4 MW and burn through approximately 500 litres of fuel every day.

In the apocryphal history of Ireland, Lebor Gabála Érenn, Tory Island was the site of Conand's Tower, the stronghold of the Fomorians, before they were defeated by the Nemedians in a great battle on the island. The later Fomorian king, Balor of the evil eye, also lived here. Balor would imprison Ethlinn in a tower built atop Tor Mór (or Túr Mór in Old Irish, meaning The High Tower). Tor Mór is the island's highest point.

A monastery was founded on Tory in the 6th century by Colmcille. The monastery dominated life on the island until 1595, when it was plundered and destroyed by English troops, who were waging a war of suppression against local chieftains. (The monastery's bell tower, built in the 6th or 7th century, is the largest structure to have survived.)

In 1608, in what is known as the Siege of Tory Island (one of the final incidents of O'Doherty's Rebellion), a group of the surviving rebels took shelter in the castle on the island, but began killing each other in hopes of securing a pardon.

The final action in the Irish Rebellion of 1798, the naval Battle of Tory Island, took place in the sea just off the island.

The first battleship the British lost during the First World War, the super-dreadnought HMS Audacious (23,400 tons), was sunk off Tory Island on 27 October 1914 by a naval mine that had been laid by the armed German merchant-cruiser Berlin. The loss was kept an official secret in Britain until 14 November 1918 (three days after the end of the war). The sinking was witnessed and photographed by passengers on RMS Olympic, the sister ship of RMS Titanic.

Since the 1950s, the island has been home to a small community of artists, and has its own art gallery. The English artist Derek Hill (1916–2000) was associated with the Tory artist community.

In keeping with a long-standing tradition, a "king" is chosen by consensus of the islanders. The most recent "King of Tory" (in Irish, Rí Thoraí) was the painter Patsy Dan Rodgers (Patsaí Dan Mac Ruaidhrí), who held the post from the 1990s until his death on 19 October 2018. The king has no legal power, but has duties that include acting as a spokesperson for the island community and welcoming people to the island.

In 2009, the island gained attention from several news outlets when a resident was awarded damages against a neighbour for demolition and removal of his house in 1993. The house had gradually disappeared over a nine-month period, while the owner worked in New Zealand. On his return, and with the house completely removed and replaced with a car park, his questions and the subsequent investigations by the police were reportedly met with a "wall of silence" from other residents. The story was featured in a book in 2012 and a BBC podcast in 2021, both titled "The House That Vanished".

In 2015, the island's only café was destroyed by fire.

The table below reports data on Tory Island's population, taken from Discover the Islands of Ireland (Alex Ritsema, Collins Press, 1999) and from the census of Ireland. Censuses in Ireland before 1841 are not considered complete or reliable.

Historical population

Year Pop. ±% 1841 399 —     1851 402 +0.8% 1861 386 −4.0% 1871 343 −11.1% 1881 332 −3.2% 1891 348 +4.8% 1901 335 −3.7% 1911 307 −8.4% 1926 250 −18.6%	Year Pop. ±% 1936 291 +16.4% 1946 265 −8.9% 1951 257 −3.0% 1956 273 +6.2% 1961 264 −3.3% 1966 243 −8.0% 1971 273 +12.3% 1979 213 −22.0% 1981 208 −2.3%	Year Pop. ±% 1986 136 −34.6% 1991 119 −12.5% 1996 169 +42.0% 2002 133 −21.3% 2006 142 +6.8% 2011 144 +1.4% 2016 119 −17.4% 2022 141 +18.5%
Source:

Tory Island has a number of sites connected with historical events and island mythology:

• Dún Bhaloir (“Balor's Fort”) is located on the island's eastern side, on a peninsula surrounded on three sides by 90-metre-high (295-foot) cliffs. The fort is accessible only by crossing a narrow isthmus that is defended by four earthen embankments.
• An Eochair Mhór (the “Big Key”) is a long, steep-sided spur jutting from the east side of the peninsula and ending in a crag called An Tor Mór (the “Big Rock” or the “Big Tower”). The spur has prominent rocky pinnacles known as “Balor's soldiers” (Saighdiúirí Bhaloir). They give the spur a 'toothed' appearance, helping to inspire the name “the Big Key”.
• The Wishing Stone is a precipitous, flat-topped rock alongside the northern cliff-face of Balor's Fort. Traditionally, a wish is granted to anyone foolhardy enough to step onto the rock, and also to anyone who succeeds in throwing three stones onto it.
• An Cloigtheach (the “Bell Tower”) is the largest structure to have survived the 16th-century destruction of the monastery (see history section above). The round tower was built in the 6th or 7th century.
• The Tau Cross (a T-shaped cross) is believed to date from the 12th century. It is one of only two Tau crosses in Ireland (the other is in Kilnaboy, County Clare).
• Móirsheisear (“Grave of the Seven”): Móirsheisear (which literally means “big six”, but is nevertheless a term signifying seven) is the tomb of seven people, six men and one woman, who drowned when their boat capsized off Scoilt an Mhóirsheisear (the “Cleft of the Seven”) on the island's northwest coast. According to local superstition, clay from the woman's grave has the power to ward off vermin.
• The Lighthouse, standing at the west end of the island, was built between 1828 and 1832 based on a design by George Halpin, a noted designer of Irish lighthouses. In April 1990, the lighthouse was automated. It is one of three lighthouses in Ireland into which a reference station for the Differential Global Positioning System (DGPS) has been installed. The lighthouse is at coordinates 55°16.357′N 8°14.964′W / 55.272617°N 8.249400°W / 55.272617; -8.249400 (Tory Island Lighthouse)
• The Torpedo: A torpedo can be seen midway between An Baile Thiar and An Baile Thoir. It washed ashore during World War II and was then defused and moved to its present location.

The island is a designated “Important Bird Area”. It is a breeding site for corn crakes (Crex crex), a globally threatened species whose numbers have fallen as agriculture has intensified. In 2007, Tory Island recorded 18 calling males, down from a recorded maximum of 34 calling males in 2003. In 2010, numbers dropped down further to 10. In addition to its indigenous birdlife, the island records many vagrants.

Ancient records of the flora and fauna of this island can be found in Hyndman's notes on the history of the island. Algae found locally include: Fucus vesiculosus, Fucus nodosus, Himanthalia lorea, Laminaria digitata, Rhodomenia laciniata, Plocamium coccineum, Ptilota plumosa, Conferva rupestrus, Codium tomentosum, Codium adhaerens det Dr Harvey.

Because of its high winds, the island has no trees.

Tory Island Cattle are a rare breed of cattle from Tory Island.

• List of abbeys and priories in County Donegal

• Tory Island travel guide from Wikivoyage