Ciboure (; , meaning 'end of bridge') is a commune in the south-western French department of Pyrénées-Atlantiques.
It lies across the river Nivelle from the harbour of Saint-Jean-de-Luz.
Ciboure was formerly known as Sibourne in English-language sources.
Ciboure has an oceanic climate (Köppen climate classification Cfb). The average annual temperature in Ciboure is . The average annual rainfall is with November as the wettest month. The temperatures are highest on average in August, at around , and lowest in January, at around . The highest temperature ever recorded in Ciboure was on 30 July 2020; the coldest temperature ever recorded was on 3 February 1956.
Ciboure and the neighbouring commune of Saint-Jean-de-Luz were suspected of "incivility" during the French Revolution and, during the Reign of Terror, were merged together under the name Chauvin-Dragon. The name was derived from a revolutionary soldier named Chauvin who, as a member of a dragoon unit, died in the region in early 1793. Although the name was in official use from 1793-1795, it was never used by the inhabitants of the communes and the two were officially separated in 1800.
The Notre-Dame de Bordagain was the only church in Ciboure from its construction in the 12th century through 1575. A tower was added in the 14th century for military purposes. During the Revolution, the church and tower fell into disrepair. The building was restored and turned into a tea house in 1911 by an architect from Saint-Jean-de-Luz. The business performed poorly and a proposal was made to turn it into a casino, which fell through. The church and tower were declared a historical monument in 1987 and were restored in 2010.