The first Holy Trinity Church in Cambridge was next to the old Roman road and was just a small thatched timber building.

The ministry of Charles Simeon (1759–1836) started when he was appointed vicar by the Bishop of Ely against the wishes of the churchwardens and congregation at the time who disliked his evangelicalism.

Apart from the repair to the lower section of the steeple in 1824 and painting and varnishing inside the church, Simeon made no structural alterations until 1834.

Then the small chancel with 14th century ribbed vaulting was demolished and replaced with the current much larger extension, constructed of brick and plaster.

In the same year, the Henry Martyn Memorial Hall was built next to the church as a centre for Christian undergraduates at the University of Cambridge.