[1] Prior to the construction of Holy Trinity, the residents of Clandown were served by the parish church of St John at Midsomer Norton.

In circa 1834, the Bishop of Bath and Wells licensed a schoolroom at Clandown to be used for services, but the increasing population led to the need for better church accommodation.

Charles Otway Mayne, the vicar of Midsomer Norton, began raising funds for a purpose-built church by grants and private subscription.

[2] Plans for the church and its parsonage house were drawn up by George Phillips Manners, with Mr. John Thatcher of Weston hired as the builder.

It has a cruciform plan and is made up of a two-bay nave, chancel, transepts, vestry, south porch, tower and bellcote.