All Hallows is a large church of ironstone and grey ashlar with an aisled and clerestoreyed nave, a 14thc. chancel with Perpendicular N and S chapels (the N now housing the organ), and a W tower with a broach spire. The c.1300 nave arcades are of four bays and there is a small S chapel off the east bay of the S aisle. Both nave doorways are under 14tc. two-storey porches. The N chancel chapel has a three-bay arcade towards the chancel, and there is a vestry to the E of it. The S chancel chapel is longer with a four-bay arcade, and an altar at its E end. The tower is of c.1250-1300 with a W doorway of that time. Its upper section and spire are of grey ashlar; the lower section banded with ironstone.

Wellingborough was held by Crowland abbey in 1086, the 5½ hide manor including a priest, so presumably a church too. Smaller holdings were in the hands of Norgiot, who held 1 virgate from the Bishop of Coutances, Hugh, who held half a hide from Countess Judith, and Gilbert who held half a virgate from the Countess. In 1201 King John granted a market here to the abbot and monks of Crowland, and this was confirmed in 1307. The abbey still held the manor in 1447 when Henry VI granted a fair.

Dedication to All Hallows recorded in 1517.

A date in the middle of the 12thc. is suggested for the S doorway.