Saint-Jacques Tower (French: Tour Saint-Jacques) is a gothic tower in Paris.
The tower was initially part of the Church of Saint-Jacques-la-Boucherie, the starting point for the religious pilgrimage to Santiago de Compostela. Nicolas Flamel, the patron of the building, was buried under the floor of the church following his death in the early 15th century.
When the church was torn down around the time of the French Revolution, the flamboyant tower built under the reign of Francis I of France was preserved. Since the tower was formerly inside the nave, and thus invisible from the outside, no ornamental decorations can be found around its base.
Saint-Jacques Tower is also a monument to science; in 1648, the mathematician and inventor Blaise Pascal conducted experiments on atmospheric pressure atop the tower.