Chapelle du Saint-Sang, Historic chapel in Bréquerecque district, Boulogne-sur-Mer, France.

Chapelle du Saint-Sang is a Neo-Gothic chapel built in 1859-1860 on Avenue John-Kennedy, designed to resemble a large reliquary. Its sculpture was carved by the London artist W. Farmer, and the stained-glass windows of 1860 were made by C. Levêque. Inside stands a replica of a 17th-century wooden bas-relief; the original is kept in the treasury of the Notre-Dame basilica.

Godfrey of Bouillon sent a relic of the Holy Blood from Jerusalem in 1101 to his mother, Ida of Boulogne, and a chapel long commemorated this event. The present neo-Gothic chapel was built in 1859–1860. The relic, donated in 1308 by King Philip the Fair for his daughter's marriage to Edward II of England, was placed in a new reliquary in 1912 and has since been kept in the chapel.

The chapel takes its name from the relic of the Holy Blood that Godfrey of Bouillon sent from Jerusalem in 1101 to his mother, Ida of Boulogne. The relic has been kept here in a reliquary made in 1912, while the 1308 shrine that once held it, donated by King Philip the Fair for his daughter's marriage to Edward II of England, is now in the treasury of the Notre-Dame basilica. A replica of the 17th-century wooden bas-relief is displayed in the chapel; legend says the original floated back upstream through the Liane after being thrown into the sea during the French Revolution.

The chapel stands at 55 Avenue John-Kennedy, on the right bank of the Liane in Boulogne-sur-Mer. It is a listed monument historique, so access is arranged around visits and Heritage Days openings; check locally before setting out. The relic is kept inside the chapel, while the 1308 shrine and the original 17th-century wooden bas-relief are held in the treasury of the Notre-Dame basilica.

The chapel is shaped like a giant reliquary. The relic arrived in 1101, sent from Jerusalem by Godfrey of Bouillon to his mother Ida of Boulogne. A 17th-century wooden bas-relief was, by legend, thrown into the sea during the French Revolution and drifted upstream along the Liane back to the shore; the chapel now holds a replica, the original being in the treasury of the Notre-Dame basilica.