The Cathedral was built between the XIII and XIV centuries by Giorgio di Como, probably on the foundations  of a Roman temple in the Roman forum area. It’s dedicated to Saint Settimio, the first bishop of the church in Jesi.

It was demolished by the bishop Fonseca and the architect Filippo Barigioni from Rome projected the new one which was rebuilt between 1732 and 1741. The image of the old Medieval cathedral  can be seen in the standard painted by Luigi Mancini and which is housed at the Diocesan Museum. In fact little is left of the old building: only two lion- shaped fonts inside the modern cathedral which were once in the portal of the church. The eighteenth-century bell tower was made by Francesco Matelicani, who was born in Jesi and who drew inspiration from the belfry built in Loreto by Luigi Vanivitelli. The façade was projected by the Roman Gaetano Morichini and it was added in 1889. Luigi Mancini partially painted the inner vault with an episode of the life of Saint Settimio. The portal was made by the Marche sculptor Paolo Anniballi on occasion of the Jubilee Year 2000.  

The cathedral has a single nave and a hemispherical dome, as typical of the widespread taste for Neoclassicism of that time.  Many side chapel were opened during the 18^th century and they were adorned with paintings, decorations and liturgical items requested by the noble families from Jesi. The wooden choir was designed by Domenico Valeri from Jesi. In the basin over the apse Biagio Biagetti from Recanati painted in 1939 the majestic image of Christ Lord of the World surrounded by Saints Florian and Romuald  to the right and Settimio and Francis from Assisi to the left.