In the interior of the triple-naved pillared basilica the tierceron, a long stretch of continuous fan vaulting resting on massive sheaved columns running as far as the east end of the choir, is allegedly the longest ribbed vaulting in the world. It has magnificent keystones and intensifies the particular character of this distinctive longitudinal English Gothic building. On the northern wall of the central nave the Minstrel Gallery built by John Gradisson (Bishop from 1327-1369) has angels playing musical instruments below baldachins still mostly in the original colors. There are attractive groups of consoles (14th century) on the pillar beyond the chancel (1687) with a storyteller offering a headstand as a present to the Mother of God on the opposite column of the central nave.
The choir screen with 17th century paintings was completed in 1325, during the Commonwealth (1649-1660) it was walled in, in order that the Independents could use the main nave and the Presbyterians could use the choir for their worship. Of particular interest are the 50 or so misericords from 1230-1270 which are integrated into the 19th century choirstalls, including an elephant with cow's feet, sirens, a king in a cauldron. Close to the high altar is a medieval sedilia (14th century) with stone baldachins. The lectern in the form of a brass eagle (symbol of John the Baptist) dates from around 1500. The splendid 55ft/17m-high Bishop's Throne is a masterpiece of Gothic wood carving (1313-1317) with panels depicting Bishops Warelwart (d. 1136), Quivil (d. 1291), Stapledon (d. 1326) and Grandisson (d. 1369), the leading architects of the cathedral. The tombs of various bishops from the 12th to the 16th centuries are located in the east choir, the ambulatory and in the Lady Chapel, some in new colorful settings.
Also noteworthy is the large east window (1320-1370) with representations of Mary and the Saints, as is the clock in the north transept; the larger face is from the end of the 15th century and the upper face was added in 1760.