St Martin (Jèrriais: Saint Martîn) is one of the twelve parishes of Jersey in the Channel Islands. It is 5.5 kilometres (3.4 mi) north-east of St Helier. It has a population of 3,948. The parish covers 10.3 km2 (4.0 sq mi).
 The parish is a mixed rural-urban community and forms the north-east corner of the Jersey rectangle. It has he easternmost point of the Bailiwick. Most of the population is concentrated in the villages of the parish and along La Grande Route de Faldouet and the coast towards St Catherine's.
 The village of Gorey is partly located in the parish, with the remainder of the village in Grouville. In Gorey, the parish hosts one of the three principal English military fortifications located in Jersey: Mont Orgeuil (Gorey) Castle. The village of Maufant is also partly located in St Martin, along the boundary with St Saviour.
 Historically it was called Saint-Martin-le-Vieux (Saint Martin the Old) to distinguish it from Saint-Martin-de-Grouville (known today as Grouille). This explains why the parish coat of arms are so similar.
 The dolmens at Le Couperon and Faldouet are among the prehistoric remains in the parish. La Pouquelaye de Faldouet features on the reverse of the Jersey ten pence coin and was the inspiration for the poem Nomen, numen, lumen written by Victor Hugo in 1855 during his exile in Jersey.
 
In 1689, William of Orange became the King of England; and England, as a Dutch ally, went to war against the French. Although due to the scale of the war, the island did not come into much focus, it was at this time the Privilege of Neutrality which had long been enjoyed by the islands was lost William had banned all trade with France, a proclamation which applied to Jersey as well, however due to corruption in the higher levels of Jersey's government, namely the Lieutenant-Governor himself Edward Harris, a large smuggling trade thrived, operating from the bailiwick. Smugglers would be alerted by a fire set by French merchants on the Écrehous reef, a part of Jersey's bailiwick, to which Jersey boats, under the approval of the Lieutenant-Governor, would travel to conduct illegal trade. Despite attempts from parish authorities to stop the boats, being that the reef was part of Jersey and that these boats had permission from the government to travel to the islets, no action could be taken.: 164–5  There is a significant oyster bed off the coast of Gorey. In the early 19th century, at least 2,000 men were employed in the industry at Gorey, and a number of cottages were built in the village to accommodate the new English residents. This also led to the construction of Gouray Church to provide English services for the residents (most of the Anglican services on the island at the time were delivered in French).:236
 The rock known as Le Saut Geffroy, or Geoffroy's Leap, is reputed to be an ancient place of execution where criminals were thrown into the sea. According to folklore, a man named Geffroy was condemned to be thrown into the sea. Remarkably, he survived and climbed back up the cliff face where an argument broke out among the mob of spectators. Some said that sentence had been duly carried out and that Geffroy should go free; others said that sentence had not been properly carried out. To settle the argument, and demonstrate his prowess, Geffroy dived off the rock, but perished on this occasion. Le Saut Geffroy is now preserved by the National Trust for Jersey.
 The parish is a first-level administrative division of the Bailiwick of Jersey, a British Crown dependency. The highest official in the parish is the Connétable of St Martin. The incumbent office holder is Karen Shenton-Stone, who has held the office since 2018. The parish administration is headquartered at the Public Hall next to the village green. St Martin is the only parish in Jersey other than St Helier not to conduct its municipal business from a Parish Hall. It has a Public Hall instead, having accepted money from the States of Jersey to provide an assembly room.[citation needed]
 At present, the parish forms one electoral district for States Assembly elections and elects one Deputy, as well as eight Senators in an islandwide constituency. The current Deputy for St Martin is Steve Luce, who ousted the long term incumbent Bob Hill in the 2011 election. Under the proposed electoral reform, it will form part of the North East electoral district consisting of St Martin and Grouville, which will collectively elect three representatives (the least of any constituency) alongside the parishes' Connétables.
 St Martin is divided into five vingtaines as follows:
 The 600m breakwater at St Catherine is all that remains of a grandiose harbour project started, but then abandoned, by the British government in the 19th century. It is now a popular site for sea anglers.
 This is one of the most agricultural parishes, and one of the most sought after places to live in the island. It has the best herd of Jersey cattle, some of the largest potato growers and a number of small farmers now cultivating the new “Genuine Jersey”, mainly organic, brand.
 The main settlements in the parish are the villages of St Martin, Maufant and Gorey. Gorey is split with Grouville. The southern half of Maufant is located within St Martin, however the main road through the village is in St Saviour.
 The Écréhous, small group of rocky islands, are also part of the parish.
 St Martin is one of the remaining strongholds of Jèrriais with a distinctive accent. The area around Faldouet formerly possessed a dialect of its own, known as Faldouais, of which the distinctive feature was the realisation of intervocalic /r/ as /z/. Although the Faldouais dialect is extinct, it has left notable amounts of writings in Jèrriais literature.
 St Martin is twinned with:
 Mont Orgeuil is one of the two main castles in Jersey. First known as Gorey Castle and located near Gorey Pier, it has existed for 800 years. The castle was subject to raids by the French in the 13th, 14th and 15th centuries. The castle served as the island's prison until a prison was constructed in St Helier in the 17th century. Among agitators imprisoned there by the British government were William Prynne and John Lilburne. Until the construction of Elizabeth Castle off St Helier at the beginning of the 17th century, Mont Orgueil was generally the residence of the Governor of Jersey.
 Gorey Pier is the eastern terminus of the A3 La Rue à Don, which is the main road linking the village to Grouville Church and to St Helier. It was formerly the terminus for the Jersey Eastern Railway.
 As part of the Eastern Cycle Network plans, Gorey Village will be connected to St Helier with a direct off-main road cycle route. A cycle path was constructed along the side of La Rue à Don in the Grouville part of Gorey in 2011. Later on, the cycle lane was extended south along the Royal Golf Course (at a cost of £190,000) and north to connect to Gorey Pier along the coast.
 St Martin has a very comprehensive green lane network, which are roads that have a 15 mph speed limit and priority is afforded to pedestrians, cyclists and horseriders. Most of the parish-owned by-roads are designated as green lanes. This compares to its neighbouring parishes St Saviour and Trinity, which have no green lanes, and Grouville, which has very few. In 2020, the Connétable Karen Shenton-Stone said St Martin had seen a huge increase in cycling during the COVID-19 lockdown.
 49°12′33″N 2°02′17″W﻿ / ﻿49.20907°N 2.03796°W﻿ / 49.20907; -2.03796