Since the Holy Trinity church was opened in 1848, it has been the focal point of worship in the parish. During this period the world has seen much political unrest and social and economic change, including two world wars. The church has provided parishioners with a centre of fellowship and spiritual refuge.
The building of the Holy Trinity church was completed in 1848 at a cost of about £2,000. The original church was rather like a large tunnel, the door was on the north side facing Greys Hill and the ventilation was poor. The nave presumably had one central aisle with the font situated at the west end. It is believed that a harmonium provided the music before an organ was installed in the south-west corner. The lighting was by gas; it was not until 1929 that electric lighting was installed. The Infants' School in Greys Hill (opposite the top of the churchyard) was probably used as a Sunday school.
The church was opened in 1848 as a daughter church is the parish of Rotherfield Greys, but Holy Trinity became a parish in its own right in 1849. The parish at that time has a population estimated at 1,000; today it is more than 7,500 comprising the larger part of Henley-on-Thames.
The church building was enlarged in 1891 to cater for the growing population on Henley. The enlargement retained its decoration of flint and stone to match the original design of Benjamin Ferrey.
The interior was re-ordered in 1987 to leave the present flexible arrangement, much enjoyed by congregation and community alike