Following the closure of the recusant chapel at Hatherop Castle in 1844 a church was built at Horcott during the following year for the cost of £700.
The first Mass was celebrated on Sunday, 12th October 1845. This was five years before the Restoration of the Hierarchy in England and before the creation of the Diocese of Clifton. The stained glass window behind the altar depicts St Thomas of Canterbury in the centre panel, with the date of 1845 still visible. The Church was dedicated on the 4th June 1991.
The adjoining Presbytery was erected twenty years later to the designs of Benjamin Bucknall, the architect of Woodchester Park. The Church contains an Organ by Hill and stained glass by Wailes, Hardman and Geoffrey Robinson.

The two windows in the porch were added to commemorate the 150th Anniversary of the first Mass. The left window depicts the crest of the de Mauley family whilst the one on the right depicts the Eucharist which has been celebrated in this church continuously for a 150 years.
From 1939 until Christmas 1998 Mass was celebrated at the Convent of St Clotilde which was situated at Lechlade Manor where there were also small, but successful, schools for both junior and secondary aged pupils. When the convent closed in late 1998 a new venue had to be found and the Methodist Church congregation was able to offer hospitality; Mass at this venue was ended in 2003.