A church school seems to have been in existence in the 1830s and presumably this was held in the north gallery of St. Mary's Church at Old Dilton. In 1848, after Holy Trinity Church had been built at Dilton Marsh, a government grant of £206 was obtained to build a new school. This was built alongside the new churchyard and run in union with the National Society. In 1858 there were 70 children being taught by an uncertified mistress and two pupil teachers. The schoolroom measured 42 feet by 21 feet and the classroom (for infants) 36 feet by 19 feet. There were tiled floors and parallel desks, and a report stated that the conditions were moderate. From 1867 there were separate schools for boys and girls within the building, with the infants being included with the girls. The master had charge of the whole school and taught the boys, while the mistress and pupil teachers taught the girls and infants. Between May 1875 and February 1876 the school was taught as a mixed school as there was no master and from 21 February 1881 the boys and girls were once more taught as a mixed school on a permanent basis.
There was quite a changeover of masters in the 1860s, '70s and '80s and despite reasonably good H.M.I reports on arriving at the school several of them seemed to have found the school in bad order, the boys with a lack of discipline and pupils having little knowledge. After the school became a mixed school the teaching structure in 1882 was: master, William Harrison; two assistant mistresses, Annie Willis and Annie Pearce; monitor for the mixed school, Henry Marshman; monitor for the infants' school, Sarah Lanfear - Sarah later qualified as a teacher.
The basic subjects taught were reading, writing and arithmetic but in the late 1860s there were also geography, scripture, history, music, singing and needlework lessons. Later drawing was added and, from 1881, domestic economy was taught. Children attended church services at least once a week, normally at 11.15 a.m. and 'night work' (homework) was given to the older children. In 1872 one history lesson was devoted to Edward the Black Prince, while the boys had some topical lessons, such as the Arctic expedition, using illustrations from the Graphic in November 1876, and the war in Turkey in 1877. In the 1870s the boys were learning songs such as 'Men of Harlech' and 'Strive to Learn', while poetry was learned for repetition and recitation. In 1883 the Standards (Standard II were the youngest) learned the following: Standard II, 'The Old Soldier', in 10 verses by M. Barr; Standard III, 'We are Seven', by Wordsworth; Standard IV 'The Fakenham Ghost' by Bloomfield; Standard V, 'Gray's Elegy in a County Churchyard' Standards VI and VII, 'Prince Arthur and Hubert' by Shakespeare.
Attendance, particularly in the boys' school in the 1870s, was fairly low and erratic. In May 1876 half-holidays were given on three days, as only six boys were present, while in July the average attendance was only 9.9 boys. By 1877 there were up to 40 boys attending as several had been admitted from the Infants, and the master was complaining that they could not cope with the number. In 1882 the mixed school had 78 on the register and in 1897 there were 42 infants and 112 children in the mixed school.
Annual holidays were one week to 12 days at Christmas, one week each at Easter and Whitsun and four weeks Harvest Holiday in the summer. Several half-day holidays would be given in the year including one after H.M.I inspections and examinations, one for the school treat in June or July and one for Ascension Day in May. Others were given for a festival at Chapmanslade in May 1868, for the Volunteers' Review on Warminster Down in July 1868, and for the recovery of the Prince of Wales from illness in March 1872.
Children, especially the older boys were often absent and frequently this was at times that they were engaged in seasonal work. This included: March, gardening; April, helping parents in the fields, picking wood, and potato planting; May, gardening; July, haymaking; September, harvesting potatoes, apples, acorns and blackberries. The Dilton Marsh September fair was also responsible for several unauthorised absences. Bad weather also meant lower numbers, be it heavy snowfall, as in January 1873, or severe rainstorms, such as those in 1882 when the school was closed on 24 October because the roads were flooded and impassable.
Various breaches of rules and misdemeanours were punished and the cane was often used. The wrongdoings included, being late, inattention during lessons, blotting their copybooks (literally), stealing a book from the church, ill temper, insolence, not doing homework, truancy, sliding on footpaths in icy weather and throwing snowballs. On one occasion five windows were broken by boys throwing balls. Sometimes the boys were forbidden to stay in the school after they had eaten their dinner as they turned over desks and muddied the room.
It was not until November 1876 that most of the pupils began to work on paper instead of slates. Equipment was often in short supply and old. In 1875/6 it was stated that the furniture in the boys room was more suited to the infants in size, with low forms and unsuitable desks.
By 1899 the school had accommodation for 200 children and the average attendance was 110. The schoolroom measured 35 feet by 18 feet by 18 feet high, the classroom 32 feet by 18 feet by 18 feet high, and the infants' room 36 feet by 16 feet by 16 feet high. The playground was 90 feet by 90 feet but because of railings only an area 90 feet by 70 feet was usable. In 1904/5 the school was taken over by Wiltshire County Council and from then was known as the Church of England School.