Local legend suggests that work on the church originally commenced at Brynyffynon but that each day's work was destroyed during the night and, as the day's work collapsed, a phantom voice was heard crying "Bryn y Grôg".
This voice was taken to be a divine indicator that the church should instead be built on the nearby hill of that name.

The church tower being blown down in 1330 was believed to have been a divine punishment arising from the town's market being held on a Sunday, which resulted in market day being moved to a Thursday.
The tower collapsed on St Catherine's day and a statue of St Catherine appears on the east wall of the tower, possible as a form of protection.

A corbel believed to depict Thomas Stanley, 1st Earl of Derby, shows him with the ears of donkey for reasons unknown.

In May 1581, the Catholic martyr St Richard Gwyn was taken to St Giles' and carried around the font on the shoulders of six men and laid in heavy shackles in front of the pulpit.
However, he 'so stirred his legs that with the noise of his irons the preacher's voice could not be heard'.

The church organ is referenced in the late-Jacobean Beaumont and Fletcher play, ‘The Pilgrim’ (1647), in which the stock Welshman declares that “Pendragon was a shentleman, marg you, Sir, and the organs at Rixum were made by relevations”.

One of the most popular hymns of the 19th century, 'From Greenland's Icy Mountains' was composed by Reginald Heber on a visit to the vicarage and was first sung in public in the church in 1819.

An unsubstantiated rumour suggests that the gravestone of Elihu Yale was stolen by the Yale University secret society, Skull and Bones, and displayed in a glass case within the society's hall known as 'The Tomb'.

The church's tower is traditionally one of the Seven Wonders of Wales, which are commemorated in an anonymously written rhyme:
Pistyll Rhaeadr and Wrexham steeple, 
Snowdon's mountain without its people,
Overton yew trees, St Winefride wells, 
Llangollen bridge and Gresford bells.

The church's tower is mistakenly called a "steeple" in the rhyme.
Local legend suggests that work on the church originally commenced at Brynyffynon but that each day's work was destroyed during the night and, as the day's work collapsed, a phantom voice was heard crying "Bryn y Grôg". This voice was taken to be a divine indicator that the church should instead be built on the nearby hill of that name. 
The church tower being blown down in 1330 was believed to have been a divine punishment arising from the town's market being held on a Sunday, which resulted in market day being moved to a Thursday. The tower collapsed on St Catherine's day and a statue of St Catherine appears on the east wall of the tower, possible as a form of protection.
A corbel believed to depict Thomas Stanley, 1st Earl of Derby, shows him with the ears of donkey for reasons unknown.
In May 1581, the Catholic martyr St Richard Gwyn was taken to St Giles' and carried around the font on the shoulders of six men and laid in heavy shackles in front of the pulpit. However, he 'so stirred his legs that with the noise of his irons the preacher's voice could not be heard'.
The church organ is referenced in the late-Jacobean Beaumont and Fletcher play, ‘The Pilgrim’ (1647), in which the stock Welshman declares that “Pendragon was a shentleman, marg you, Sir, and the organs at Rixum were made by relevations”.
One of the most popular hymns of the 19th century, 'From Greenland's Icy Mountains' was composed by Reginald Heber on a visit to the vicarage and was first sung in public in the church in 1819.
An unsubstantiated rumour suggests that the gravestone of Elihu Yale was stolen by the Yale University secret society, Skull and Bones, and displayed in a glass case within the society's hall known as 'The Tomb'.
The church's tower is traditionally one of the Seven Wonders of Wales, which are commemorated in an anonymously written rhyme:
Pistyll Rhaeadr and Wrexham steeple, 
Snowdon's mountain without its people,
Overton yew trees, St Winefride wells, 
Llangollen bridge and Gresford bells.
The church's tower is mistakenly called a "steeple" in the rhyme.
St Giles' Church, Wrexham