[1] Holy Trinity was built in 1839–40 as a chapel of ease to the parish church of St John the Baptist in Broadwindsor.

The church at Blackdown was built in a location central to approximately 400 inhabitants who were around three miles from St John.

[3] The plans for the church were drawn up by Edward Ledger Bracebridge of London (the only example of his work in Dorset).

The rest of the required funds were raised within the parish, including at a sale of work held in the grounds of Blackdown House on 6 June.

[7] The church was closed for three weeks during September and October 1894, while the restoration work was carried out by Mr. Cooper of Bridport.

[8] The debt from the restoration was cleared with a sale of work held at Blackdown National School in July 1895.

[10] During the night of 16–17 December 1961, the church was gutted by fire, which started from the wood-burning stove that had been lit during the day in anticipation of the following Sunday morning service.

[11][12] The 50th anniversary of the church's reopening was celebrated with a thanksgiving service led by the Bishop of Sherborne, the Right Rev.

[2] The church is made up of a nave and chancel under one roof, a north vestry and south porch.