Lands around Grittleton were owned by the monks of Glastonbury Abbey in Anglo-Saxon times. During the 16th century the clergy were in turn Catholic or protestant, according to which monarch was on the throne. Records list clergymen as far back as 1269, and Rev. Jackson, in his book, suggests the nave of the church dates from around 1380, with the tower at a later date.
In 1667 the Church Wardens were John Jaques and John Bonnet of Foscote, and repairs to the tower in 1672 cost 8/-, eight shillings (40p.) the Church Wardens in 1799 are recorded as Antony Allen and Isaac Turk.
The chancel was rebuilt in 1805 by Rector Burne, who, at his own expense, added a new aisle and porch on the south side. The cost was £1,000, and the architect was John Pinch. A font of Painswick stone was installed. However, by 1862 the exterior of the tower needed repair. During the period 1805-10 various pieces of silver were donated to the church.
During 1835/6 the Neeld family had a large pew installed in the church, furnished with velvet chairs and having a fireplace at each end. 1858 saw the purchase of a new organ. In 1865 the nave and chancel were restored. The panelling around the Baptistery originated from Surrendel farm, and the existing screen was replaced by one removed from Leigh Delamere Church. At this time gas light was installed. All this work was funded by the Neeld family, the architect was A.W.Bloomfield, and superintendents were Mr Chivers and Mr Hulance of Alderton.
In 1867 it was necessary to re-roof the north aisle and new windows were installed in the old walls. A memorial window was installed by the rector, in memory of his mother The memorial window to Jos. Neeld was installed in 1876, when the chancel aisle and vestry were built with the organ being removed from the west end of the north aisle. At the same time a memorial window of stained glass and to the memory of Rosina Patton (sister of Sir John Neeld) was installed. In September the chancel aisle was opened, the choir was situated in the chancel, and cassocks and surplices introduced. The coloured stoles were introduced in 1880, and that year saw the demolition of the tithe barn. 1881 saw the re-building of the unsafe south west turret, and at Christmas, carols were sung, after evensong, for the first time. The stone pulpit from Leigh Delamere was installed at Grittleton, and the old Jacobean pulpit from Grittleton was donated to Wantage, at the same time a new aisle and north gallery were donated by Lady Neeld in memory of Sir John, this was re-dedicated in 1892, with a new east window by created by Heaton and Butler.
The bells were re-hung in1865 by White of Abingdon.. Number 4 bell has an inscription dated 1627, whilst number 1 is inscribed 1718. In 1906 Sir A. Neeld donated a new bell. A new South Aisle and North Gallery, together with new pews were completed, and a new organ was purchased in 1858, when a yew hedge was planted along the south wall. 1921 saw electricity installed in the Church.
The Clergyman’s Register of 1892 notes that one Walter Bolder, who had previously fallen from a bridge on the Manchester Ship Canal, came and gave thanks for the preservation of his life, in Grittleton Parish.
The parish registers from1577 (christenings) and 1573 (marriages and burials) are held in the Wiltshire & Swindon History Centre at Chippenham.