The Jesuit Church of St-Pierre, built between 1608 and 1614, is the most ornate church in the Ajoie and an example of the early Baroque style that the Jesuits brought to the border regions of the Holy Roman Empire. The interior is richly decorated with stucco work and gilded altarpieces — a deliberate contrast with the plain Reformed churches across the border in the nearby Bernese Jura.
The church sits at the heart of the old town, close to the central fountain square. The Jesuits established themselves in Porrentruy at the invitation of the Prince-Bishops, who wanted an educated religious order to counter the spread of Protestantism in the region. The church is open for visits outside service hours.