Formerly a chapel of ease for Taney Church of Ireland parish, St. Thomas's Church Foster Avenue was opened in 1874 is now part of the parishes of Booterstown and Mount Merrion.
The Church is described in "The Parish of Taney" by Francis Elrington Ball & Everard Hamilton, 1895 as follows : 'The building is in the form of a single aisle, with a suitable chancl at the east end; it is in the pointed style, in granite, with cut stone dressings to the door,windows and coigns. The interior is fitted with a pitch-pine pulpit, reading desk, communion rails, and pews, and is supplied with a harmonium.
The chancel contains a painted window, representing Christ blessing little children, and two side lights. A brass tablet 'upon the north wall bears the following inscription : - To the glory of God, and in loving memory of Thomas Crozier and Mary, his wife, or Seafield, County Dublin, these windows have been placed by their children, June 1876"
A marble tablet on the south wall was erected - "In memory of Edward Perceval Westby, D.L. or Roebuck Castle, Co. Dublin, and Co. Clare, who entered into rest April 22nd 1893, aged 64. The Lord always did lead him . Duet. xxxii, 18. The beloved of the Lord shall dwell in safety. Duet xxxiii, 12" '