Along the Via Ostiense onthe spot were by tradition the Apostle of the peoples was buried, the early Christians built a burial chapel (cella memoriae) that was later transformed into a basilica by Constantine. Always by tradition the basilica was consecrated in 324 by pope Sylvester the First. 

The reconstruction to make the temple larger was started in 385 and completed in 395 at the time of emperor Honorius. It soon became one of the most important stopping places of pilgrimages to Rome. 

The large basilica presents three naves with ancient columns and forty-two windows illuminating the interior. A borough developed around the basilica due to Saracen raids in the ninth century and was fortified later by pope John the Eighth after whom it was called Giovannopoli. 

In the course of centuries the basilica was enriched with splendid works of art. The magnificent bronze doors cast in Constantinople by skilled Byzantine workers were donated in 1070. They are still in situ, but turned inwards. The Vassalletto, a family of marble workers, were active in the church in the thirteenth century. 

Also active were Arnolfo di Cambio, author of the ciborium, and Pietro Cavallini, whose fresco decorations in the nave and mosaic decorations on the facade have unfortunately gone completely lost. 

Further interventions were performed in the fifteenth century (by Benozzo Gozzoli and Antoniazzo Romano) and seventeenth century (by Onorio Longhi and Carlo Maderno). Between August 15 and 16 1823 the basilica was nearly destroyed by a fire that spared only the transept and part of the facade. 

The committee instituted by pope Leo the Twelfth decided to rebuild the temple completely after examining different solutions. Pasquale Belli was assigned the task of doing the works and in collaboration with other architects he demolished the remaining parts and rebuilt the church as it looks today (1825-1854) following the sizes and the plan of the ancient basilica.

The upper order of the facade is decorated with nineteenth century mosaics by Luigi Poletti – who is also the author of the bell-tower and of the pronaos on the north side. The pronaos was built reusing twelve columns that were part of the nave of the ancient church - and is preceded by a large quadriportico, designed at the end of the past century by Virgilio Vespignani. 

At the centre of the quadriportico stands the statue of Saint Paul by Giuseppe Obici. The interior is divided in five naves by eighty monolithic granite columns (the six ones in the entrance hall donated by the viceroy of Egypt to Gregory the Sixteenth are outstanding). 

The larger central nave presents mosaics on the walls with portraits of popes that continue also in the side naves, and frescoes of the story of the life of Saint Paul. The Triumphal Arch decorated with fifth century mosaics, unfortunately extensively restored, closes the central nave. 

The high altar is surmounted by the famous gothic ciborium by Arnolfo di Cambio (1285), consisting of four red porphyry columns that support the roof decorated with statues in the corners and colored mosaics. Ahuge marble candelabrum for the Easter candle made by Nicola D’Angelo and Pietro Vassalletto in 1170 is placed  on the right of the altar. 

The apse is dominated by the majestic mosaic commissioned by Innocent the Third (1198-1216) and terminated under Honorius the Third (represented in miniature at the feet of Christ benedictive and among the Saints Peter, Andrew, Paul, and Lucas). 

In the lower level we find Apostles, a bejewelled Cross and Instruments of Passion. Extensively restored fragments of the mosaics by Cavallini that decorated the ancient facade are kept outside of the apse. The tomb of Pietro Cavallini and two works of great value that luckily survived the fire in 1823 (a fourteenth century crucifix, also attributed to Cavallini, and a much venerated end of the thirteenth century wooden statue of Saint Paul) are kept in the nearby Chapel of the Holy Sacrament, designed by Carlo Maderno perhaps with some contribution by the young Borromini. 

The transept gives access to one of the most beautiful cloisters in Rome built in the thirteenth century by Vassalletto with rich and variegated small twin columns supporting small arches, that support a trabeation decorated with polychromatic tarsias and mosaics. 

Many architectural fragments coming from the ancient basilica and archaeological findings from the nearby Ostiense burial ground are kept in the cloister: of particular interest is the sarcophagus of Pietro Leone (twelfth century) decorated with scenes of the challenge and torture of Marsia. 

Two lunettes with portraits of popes frescoed by Lanfranco (1624) in the adjacent picture gallery that were previously situated in the Chapel of the Holy Sacrament are of particular interest.