Gw mau tau Interior dari Katedral St Paul. Jelasin dalam bahasa melayu

Internally, St Paul's has a nave and choir in each of its three bays. The entrance from the west portico is through a square domed narthex, flanked by chapels: the Chapel of St Dunstan to the north and the Chapel of the Order of St Michael and St George to the south. The nave is  in height and is separated from the aisles by an arcade of piers with attached Corinthian pilasters rising to an entablature. The bays, and therefore the vault compartments, are rectangular, but Wren roofed these spaces with saucer-shaped domes and surrounded the clerestorey windows with lunettes. The vaults of the choir are decorated with mosaics by Sir William Blake Richmond.  The dome and the apse of the choir are all approached through wide arches with coffered vaults which contrast with the smooth surface of the domes and punctuate the division between the main spaces. The transepts extend to the north and south of the dome and are called (in this instance) the North Choir and the South Choir.

The choir holds the stalls for the clergy, cathedral officers and the choir, and the organ. These wooden fittings, including the pulpit and Bishop's throne, were designed in Wren's office and built by joiners. The carvings are the work of Grinling Gibbons who Summerson describes as having "astonishing facility", suggesting that Gibbons aim was to reproduce popular Dutch flower painting in wood. Jean Tijou, a French metalworker, provided various wrought iron and gilt grills, gates and balustrades of elaborate design, of which many pieces have now been combined into the gates near the sanctuary.

The cathedral is some  in length (including the portico of the Great West Door), of which  is the nave and  is the choir.

The width of the nave is  and across the transepts is . The cathedral is slightly shorter but somewhat wider than Old St Paul's.