To the south of the old chancel is St Catherine’s Chapel. This small chapel is thought to be of 14th century origin. It was restored between 1890 and 1909 and the stained glass and the alabaster reredos date from this time.

At the altar, the reredos is a nativity scene showing Mary and Joseph standing over the infant Jesus, carved in the late medieval style. It is a copy of the 15th-century high altar screen of Winchester Cathedral.
The east window (above the altar) celebrates Holy Baptism, Holy Orders and Holy Eucharist. It is by another successful Victorian stained glass firm – Heaton, Butler & Bayne – who also designed the great west window in the nave.
The tracery of the St Catherine Chapel window appears to be of a medieval origin, designed with a reticulated (net-like) pattern which was fashionable in the Decorated period (early 14th century), however it is uncertain whether the tracery is medieval or was inserted during Wyatville’s restoration of the church in the 1820s.