St Paul's was Byrne's first church. The cornerstone was laid on St Patrick's Day 1835 by the archbishop of Dublin,
Dr Daniel Murray.
Exterior The church was designed by Patrick Byrne and built between 1835 and 1844, not long after
Catholic emancipation. The front has a granite portico with four Ionic columns. The three-stage Italianate bell tower, with its copper dome, was completed in 1843 and is a visual focal point along the quay, except where blocked by the dome of the
Four Courts to the east. The inclusion of a clock, less common in Catholic Churches, implies a sense of public responsibility thus increasing the status of the building. St Paul's contains a peal of eight bells cast by James Sheridan, of the Eagle Foundry, Church Street. These were originally hung for
change ringing for most of their existence; however, they were converted into a chime (operated by one person only) in 1950, and can no longer be rung full circle. A statue of St. Paul above the portico tops the apex, flanked by statues of SS. Peter and Patrick. The statues are the work of Joseph Robinson Kirk and were added about 1870. The large centre door leads to the church proper, while the smaller doors on either side give access to the balcony. Barred gates have been added to the portico to prevent homeless people from sheltering under it.
Interior The entrance hallway, inside the main door, has a mosaic floor. a marble baptismal font is in the rear of the nave. It has a shallow barrel-vaulted coffered ceiling. Steps to the altar are of marble, as is the altar itself. The mural above the altar is a copy of Rubens' Conversion of St. Paul, done by
F. S. Barff around 1863, which replaced an earlier depiction of the crucifixion. The apse is lit by a skylight. ==People associated with St. Paul's Arran Quay==