Padstow (/ˈpædstoʊ/; Cornish: Lannwedhenek) is a town, civil parish and fishing port on the north coast of Cornwall, England, United Kingdom. The town is situated on the west bank of the River Camel estuary, approximately 5 miles (8.0 km) northwest of Wadebridge, 10 miles (16 km) northwest of Bodmin and 10 miles (16 km) northeast of Newquay. As well as Padstow itself, the parish also includes the village of Trevone and surrounding rural areas. At the 2021 census the population of the parish was 2,669 and the population of the built up area was 2,298.

The geology of the low plateau west of Padstow has resulted in such features as Tregudda Gorge where erosion along the faultline has caused sheer cliffs to form; and Marble Cliffs which has alternating dark grey and light grey strata. The Round Hole is a collapsed sea cave.

In English, Padstow was originally named Adelstow after Æthelstan who was reported by John Leland to be 'chief governor of privileges onto it'. Adelstow was commuted into Petroc-stow, Petroc-stowe, or 'Petrock's Place', after the Welsh missionary Saint Petroc, who landed at Trebetherick around AD 500. After his death a monastery (Lanwethinoc, the church of Wethinoc, an earlier holy man) was established here which was of great importance until Petroces stow (probably Padstow) was raided by the Vikings in 981, according to the Anglo-Saxon Chronicle. Whether as a result of this attack or later, the monks moved inland to Bodmin, taking with them the relics of St Petroc. The cult of St Petroc was important both in Padstow and Bodmin.

Padstow is recorded in the Domesday Book (1086) when it was held by Bodmin Monastery. There was land for 4 ploughs, 5 villeins who had 2 ploughs, 6 smallholders and 24 acres of pasture. It was valued at 10 shillings (half of a pound sterling).

In the medieval period, Padstow was commonly called Aldestowe ('old place' in contrast to Bodmin, the 'new place'). or Hailemouth (heyl being Cornish for 'estuary'). The modern Cornish form Lannwedhenek derives from Lanwethinoc and in a simpler form appears in the name of the Lodenek Press, a publisher based in Padstow.

Padstow had considerable importance in the middle ages as a manor belonging to Bodmin monastery and as the site of a safe haven (one of the few on the north coast). So it became a busy fishing port and the site of nine chapels in addition to the parish church. The manor was leased to the family of Prideaux by the last prior before the dissolution in Henry VIII's reign. The town prospered through trade with Ireland and the English and Welsh ports on the Bristol Channel. Later trade was the export of tin, copper, lead, slate, cured fish and dairy produce, as well as the importing of timber from Norway and Sweden, salt and wine from France, and hemp, iron and jute from Russia. The population in 1841 was 1,791.

In the first half of the 19th century it was a significant port of embarcation for emigrants, particular those bound for Canada. Later on a shipbuilding industry developed with five shipyards though by 1900 this had declined. The North Cornwall Railway reached Padstow in 1899, a large hotel was built and there was a revival of the fishing industry.

The seal of the borough of Padstow was a ship with three masts, the sails furled and an anchor hanging from the bow, with the legend "Padstow".