Chartres Cathedral, also known as the Cathedral of Our Lady of Chartres (French: Cathédrale Notre-Dame de Chartres), is a Roman Catholic church in Chartres, France, about 80 km (50 miles) southwest of Paris, and is the seat of the Bishop of Chartres. Mostly constructed between 1194 and 1220, it stands at the site of at least five cathedrals that have occupied the site since the Diocese of Chartres was formed as an episcopal see in the 4th century. It is in the High Gothic and Romanesque styles.

The cathedral was designated a World Heritage Site by UNESCO in 1979, which called it "the high point of French Gothic art" and a "masterpiece".The cathedral is well-preserved and well-restored: the majority of the original stained glass windows survive intact, while the architecture has seen only minor changes since the early 13th century. The building's exterior is dominated by heavy flying buttresses which allowed the architects to increase the window size significantly, while the west end is dominated by two contrasting spires – a 105-metre (349 ft) plain pyramid completed around 1160 and a 113-metre (377 ft) early 16th-century Flamboyant spire on top of an older tower. Equally notable are the three great façades, each adorned with hundreds of sculpted figures illustrating key theological themes and narratives.

Since at least the 12th century the cathedral has been an important destination for travellers. It remains so to the present, attracting large numbers of Christian pilgrims, many of whom come to venerate its famous relic, the Sancta Camisa, said to be the tunic worn by the Virgin Mary at Christ's birth, as well as large numbers of secular tourists who come to admire the cathedral's architecture and historical merit.

The venerated Black Madonna enshrined within was Pontifically crowned by Pope Pius IX on 31 May 1855.