Fowey (/ˈfɔɪ/ ^ⓘ FOY; Cornish: Fowydh, meaning beech trees) is a port town and civil parish at the mouth of the River Fowey in south Cornwall, England, United Kingdom. The town has been in existence since well before the Norman invasion, with the local church first established some time in the 7th century; the estuary of the River Fowey forms a natural harbour which enabled the town to become an important trading centre. Privateers also made use of the sheltered harbourage. The Lostwithiel and Fowey Railway brought China clay here for export. At the 2021 census the population of the parish was 2,244 and the population of the built up area was 2,069.

The Domesday Book survey at the end of the 11th century records manors at Penventinue and Trenant, and a priory was soon established nearby at Tywardreath. c. 1300 the prior granted a charter to people living in Fowey itself. This medieval town ran from a north gate near Boddinick Passage to a south gate at what is now Lostwithiel Street; the town extended a little way up the hillside and was bounded on the other side by the river where merchants had their houses backing onto the waterfront. The natural harbour allowed trade to develop with continental Europe and local ship owners often hired their vessels to the king to support various wars, although the town also developed a reputation for piracy, as did many others at this time. A group of privateers known as the 'Fowey Gallants' were given licence to seize enemy vessels during the Hundred Years' War. In the 14th century the harbour was defended by 160 archers; after these were withdrawn, two blockhouses were built, one on each side of the harbour entrance. Despite these defences the town was attacked by Breton pirates in 1457. Place House, by the church, was successfully defended against the French but subsequently strengthened. This building still exists, but much remodelled. A small castle was built on St Catherine's Point, the western side of the harbour entrance, around 1540. The defences proved their worth when a Dutch attack was beaten off in 1667.

The people of Fowey generally sided with the Royalists during the English Civil War, but in 1644 the Earl of Essex brought a Parliamentarian army to Lostwithiel and occupied the peninsula around Fowey. In August, a Royalist army surrounded Essex's troops and King Charles I himself viewed Fowey from Hall Walk above Polruan, where he came close to being killed by a musket shot. On 31 August, the Parliamentarian cavalry forced their way through the Royalist lines and retreated towards Saltash, leaving the foot soldiers to be evacuated by sea from Fowey. Essex and some officers did indeed escape, but the majority of the force surrendered a few days later near Golant and were then marched to Poole, but most died before reaching there.

There was a Barbary raid on Fowey in 1645, with 240 men, women, and children captured as slaves.

The fortunes of the harbour became much reduced, with trade going to Plymouth and elsewhere instead. Fishing became more important, but local merchants were often appointed as privateers and did some smuggling on the side. Tin, copper and iron mines, along with quarries and china clay pits became important industries in the area, which led to improvements at rival harbours. West Polmear beach was dug out to become Charlestown harbour circa 1800, as was Pentewan in 1826. Joseph Austen shipped copper from Caffa Mill Pill above Fowey for a while before starting work on the new Par harbour in 1829. Fowey had to wait another forty years before it saw equivalent development, but its natural deep-water anchorage and a rail link soon gave it an advantage over the shallow artificial harbours nearer to the mines and china clay works. Meanwhile, a beacon tower was erected on the Gribben Head by Trinity House to improve navigation into Fowey and around Par bay.

The Fowey Harbour Commissioners were established by an Act of Parliament in 1869, to develop and improve the harbour. On 1 June in that year, the 7 ft (2,134 mm) broad gauge Lostwithiel and Fowey Railway was opened to new jetties situated above Carne Point, and in 1873, the 4 ft 8+1⁄2 in (1,435 mm) standard gauge Cornwall Minerals Railway (CMR) opened a line from Newquay and Par to further jetties between Caffa Mill Pill and Carne Point. Both of these railways initially carried just goods, but on 20 June 1876, a passenger station was opened on the CMR on land reclaimed from Caffa Mill Pill. The Lostwithiel line closed at the end of 1879 but was reopened by the CMR as a standard gauge line in 1895, and the short gap between the two lines at Carne Point was eliminated. Passenger trains from Par were withdrawn after 1934 and from Lostwithiel in 1965. The Par line was subsequently converted to a dedicated roadway for lorries bringing china clay from Par after which all trains had to run via Lostwithiel.

The Royal National Lifeboat Institution established Fowey Lifeboat Station near the Town Quay in 1922 to replace an earlier station at Polkerris. This was replaced in 1997, by a new facility in Passage Street. Two lifeboats are stationed at Fowey: Maurice and Joyce Hardy, a Trent Class all weather boat that is kept afloat opposite the lifeboat station, and Olive Two, an IB1 inshore lifeboat kept inside the station and launched by davit.

Fowey was the main port for loading ammunition for the US 29th Division that landed on Omaha Beach on D Day during the Second World War. There was a munitions siding at Woodgate Pill just north of Fowey, originally built for the Great War conflict.