There has been a church on this site for more than 800 years and the present building dates from the 13th century. The village of Wenvoe grew up around the church of St Mary. It began as a farming settlement but is now a dormitory town for the city of Cardiff. It has a strong community spirit and the church is still an important feature. It has had many changes and additions over the years. The tower was moved from the north side of the church to the east in 1699. In 1880 the organ chamber and vestry were added and in 1991 a new transept was built.
In 1901 the reredos at the rear of the altar was gifted to the church by William Walter Nell to mark his 28yrs as a churchwarden
The statue of the Virgin Mary and Child was installed over the entrance way in 1932
The memorial entrance gate from Old Port Road was erected in 1930 in memory of Laura Jenner of Wenvoe Castle
Above the doors to the tower vestry is a modern stained glass window which fills the arch. The window was designed by Frank Roper from penarth who also designed the west window at St Peters in Dinas Powys and two of the windows at St Michaels in Michaelston-le-Pit.
The window in St Marys depicts a Jesse Tree which has an image of the Virgin Mary and child within its branches. The two crowns of David and Solomon are prominent amongst the grapes and vine leaves.