The Revd William Bouverie Trevelyan was born on 25 June 1853 in Culverton, Buckinghamshire and was the eldest son of the Revd William Pitt Trevelyan. His family came from Nettlecombe, Somerset and had aristocratic links. His mother was the grand-daughter of the second earl of Radnor. He was educated at Trinity College, Cambridge (BA 1876, MA 1879) and was ordained an Anglican deacon in 1877, and priest in 1878. He was the Curate of Calverton for his father. Before coming to St Matthew’s in 1884, he was Vice-Principal of Ely Theological College. 
His incumbency marked a period of much development at St Matthew’s and he was able to build on the foundations which had been laid by his two predecessors. Details of his work in the parish are given in other sections of the website.
The Revd Richard Malone, included a description of Trevelyan by the Bishop of London:
‘Trevelyan was a true saint, if ever there was one, I always felt even to look at him did one good’. 
Although an Anglo-Catholic, he was tolerant of other views within the Church:
‘I have always recognised that the Prayer Book is capable of two interpretations and if I am allowed scope for mine, I cheerfully allow other people to have theirs’.
C B Mortlock, mentioned that it was Trevelyan ‘who was to make St Matthew’s famous’. 
After leaving St Matthew’s, Westminster, he became Warden of Liddon House between 1914 and 1927 was warden of the retreat house at Beaconsfield, Kidlington, Oxford.