Originally just 'St Teilo's', the church was one of several built in Cathays in the opening decades of the 20th century with the intent of servicing the large numbers of working people in the growing district. The Cathays Methodist Church, Woodville Baptist Church and Cardiff International Church are all nearby. The church began life as a tin tabernacle in 1879. This structure, built to serve the large numbers of railroad workers who lived in the district, was enlarged in 1885. St Teilo's was formed as a separate parish, together with St Andrew's Church, St Andrew's Crescent, in 1884. Work began on the permanent church in 1895, with £3000 being contributed to the project by the Mackintosh of Mackintosh. The aisles and nave were dedicated in 1897. The chancel was added in 1901. The architect's original plans had included a grand tower of similar dimensions to that of St John's in Cardiff city centre. The tower was begun in 1913, but the plans proved overambitious, and only the lowermost portion of the tower was ever built — which does not even stretch above the roof of the nave. The reredos was installed by John Coates Carter in 1924. The church became Grade II listed in 1975. The west window of the nave, which dates from 1919, is the largest in the Diocese of Llandaff. In 1954 St Andrew's Church closed and the congregation joined with St Teilo's.
The church is now in the Parish of Cathays, formed in 2007. Also placed in the new parish was the nearby church of St Michael & All Angels. This was erected on Whitchurch Road in 1922 as the successor to the combined school and chapel dedicated to St Monica which had opened in 1893. The 1922 structure was a tin tabernacle, which lasted in use until the 1990s. In 1995, a development partner was found and the church moved to a new building located on the corner of Whitchurch Road and Gelligaer Street, directly beside its former location, which is now occupied by a block of retirement flats.
Ethos
The church is a strong advocate of the Inclusive Movement, and promotes work with the LGBT community. It runs the "Meeting Room Cafe," every first Saturday of the month.
