The Welsh name Llanbadrig means "Church of Saint Patrick". This church, founded in 440 AD, has a direct link to the patron saint of Ireland. The then Bishop Patrick was sent by Pope Celestine to Ireland to convert the Irish to Christianity during the 5th Century.

Local legend states that Patrick was shipwrecked on Ynys Badrig, (Patrick's Island - also known as Middle Mouse), which can be seen from the stile in the churchyard wall.

He succeeded in crossing to Anglesey, landing at Rhos Badrig (Patrick's Moor) and finding refuge  in Ogof Badrig (Patrick's Cave).

The cave is situated below the churchyard and had a freshwater well - Ffynon Badrig (Patrick's Well). The fresh water allowed Patrick to recover from his ordeal and he founded the church as thanks to god.

The church is a simple building, 60ft. long by 14ft wide (18.5m x 4.3m) and has resisted the elements for centuries. The earlier church would have been smaller and built of wood. It is probable that this early church, like most native Celtic churches had no division between the nave and the chancel. The chancel arch was built later in the 14th century. The earliest stone on this site is the top of the font, which was made in the 12th century.

The stonework of the east window dates from the 15th or early 16th centuries - it was probably around this time that the the church was enlarged to its present size.

Moslem influences within the church included the predominance of blue, red and white in the stained glass windows, the blue glass of the east window, the blue tiles around the sanctuary and the Pastor Bonus mosaic. Both the blue tile in the sanctuary and the mosaic were custom produced by a very exclusive London firm who have also worked in St. Margaret's, the chapel of Westminster.