There has been a Christian place of worship on the site of St Marys' since at least 681 AD, and is believed to have been the location of Abbess Tetta’s Monastery (some scholars suggest this is the origin of the name Tetbury). The current church replaced the medieval church which, with the exception of the tower and spire, was demolished in 1777. The replacement church was designed by Francis Hiorn of Warwick, and was opened in 1781. It is one of the earliest and best examples of Georgian Gothic churches in the country. Since 1781, the church has undergone several changes, the most significant being in 1901 and 1993. This last restoration attempted to undo much of the "Victorianisation" and restore the interior, as far as possible and practicable, to its original Georgian plan.
St Saviour’s Church is also in the parish, currently under the care of the Churches Conservation Trust. As a church for the parish poor this magnificent Victorian church was built in a fabulously ornate medieval style and was intended for the poor of the parish, who could not afford to pay for seats in the parish church. Constructed of local stone, it was designed by a local architect Samuel Dawkes, assisted by A W Pugin and John Hardman.