The building consists of a clerestoreyed nave, north and south aisles, a chancel and west tower.

[5] At some stage, probably in the 18th century, the lower parts of the north arcade piers were encased in neo-classical plinths.

The spire appears to have been left as a stump by the medieval builders but in the 18th century was provided with an unusual climax in the form of a large copper ball mounted on a king post and four supports and topped by a weather vane.

The story goes that on the eve of the Battle of Naseby some of the king's lifeguards were sitting down to supper at the table when they were surprised by Cromwell's troops.

In 2013, BBC News reported plans to open a visitor and community centre in part of the church building, which would enable the Naseby Battlefield Trust to increase awareness of the Battle of Naseby whilst maintaining an active place of worship with up-to-date facilities.