Holy Trinity Church was built in 1851-52 on land given by the Evelyn family, Lords of the Manor of Westcott. The new parish, with a population of about 1000, had hitherto been part of the large parish of Dorking. The church was built to a design chosen by Sir George Gilbert Scott in 14th Century Gothic or Decorative style, mainly in dressed flint and with a shingled spire. It provided seating for about 250. The cost of the building was raised by subscription and Mr Charles Barclay of Bury Hill was the principal benefactor. The patronage of the living was vested in Mr Barclay and remained in the family until 1992 when it was transferred to the Lord Bishop of Guildford.
Until the formation of the Diocese of Guildford in 1927, Dorking was part of the Diocese of Winchester, and the church was consecrated by the Bishop of Winchester in 1852.
The church consists of a nave, chancel and sanctuary with a south aisle that was added in 1855. The vestry at the south east corner was a further addition and this was enlarged in 1985 by the addition of an 'upper room'.
The original organ was installed in the north chancel in 1872. The present organ was built in 1958 and was enlarged and refurbished in c.2000. The unusual mosaic reredos of coloured figures on a gold background was erected in 1882, and the commandment panels were put in a year later.
Seating in the side chapel originally faced north, as is often the case, but in 1936 the north facing pews were removed and the chapel turned into a Lady Chapel. This was enclosed and all pews removed from the south aisle in 2002 to provide greater flexibility. The colourful dossal and altar frontal were embroidered in 1995. The carved wood angels were brought from Oberammergau by a member of the congregation. The beautiful picture of the Madonna and child by Sassoferrato that hangs on the south wall was a gift from the Barclay family (it is a photograph; the original can be seen in the Treasury of Guildford Cathedral).
The porch was enclosed by new oak doors in C.2000.
The west end was enclosed in c.2004 to provide a crèche room. This entailed moving the Second World War Memorial to a more appropriate place on the south wall, and the font to a more prominent position by the north entrance.
Screen and projection facilities were added in c. 2006.
The outstanding window in the church is the beautiful east window depicting the Ascension. This was the work of James Powell & Son (Whitefriars) Limited and was given by Miss Barclay of Rokefield in 1893.
The window on the north side of the sanctuary showing scenes from the life of St Timothy is a memorial to Fredrick Henry Salzmann, Vicar of Westcott from 1910 to 1944, and that on the south side commemorates Charles Maine who died in 1888. Beside the pulpit, a window depicting St Cecelia, the patron saint of music, is in memory of Mary Ellen Druce of Rokefield. The adjacent window on the north wall commemorates the Marchioness of Hertford who lived at Brooklands.
Ten windows were destroyed by enemy action in 1940, and these were replaced with plain leaded lights. Two small panels in the west window are remains of the Leslie Memorial Window, one of those lost in the bombing. Lady Mary Leslie was one of the original benefactors of the church.
The marble war memorial on the south wall names those members of the parish who lost their lives serving in the Great War of 1914-1918. The carved wooden memorial commemorates those members of the forces who fell in the Second World War (1939-1945) and members of the village who were killed by enemy action.
Two standards of the Royal British Legion are laid up in the church reminding us that until 1986 Westcott had its own branch of the Legion, now incorporated in the Dorking Branch.
On the north wall of the chancel is a carved relief of the Happy Warrior from the studio of G F Watts in memory of a young officer from the village who was killed on the Somme in 1916.
The clock was installed to commemorate Queen Victoria's Golden Jubilee in 1887, and the lych gate was erected three years later.
An extension churchyard, on the far side of Logmore Lane, was consecrated in 1928 and extended in 1977. A Garden of Remembrance was established in 1965 and this was extended in 1988. The names of those whose ashes are interred here are recorded in a Book of Remembrance kept in the Lady Chapel.
The “Scott Brooks Gate” was installed in 2015 by Steve and Madeleine Brooks in memory of their son.
A railing through the churchyard to the south of the church was installed in 2016 in memory of Jill Crips Villiers.
St John's Chapel was founded in 1840 as a 'Countess of Huntingdon Connexion' free church, with a gift by the Worsfold family.
The present church hall was built in the late 1960's.
Holy Trinity completed the purchase of the St Johns site in 2009, after several years renting.