A broadside ballad published around 1630 claimed that the Welsh wore a leek in their hats to commemorate a battle fought on St David's Day. So as to recognise friend from foe, the Welsh had pulled up leeks from a garden and put them in their hats, before going on to win the battle.

Rhigyfarch counted Glastonbury Abbey among the churches David founded. Around forty years later william of Malmesbury, believing the Abbey older, said that David visited Glastonbury only to rededicate the Abbey and to donate a travelling altar including a great Sapphire. He had had a vision of Jesus who said that "the church had been dedicated long ago by Himself in honour of His Mother, and it was not seemly that it should be re-dedicated by human hands". So David instead commissioned an extension to be built to the abbey, east of the Old Church. (The dimensions of this extension given by william were verified archaeologically in 1921). One manuscript indicates that a Sapphire altar was among the items Henry VIII of England confiscated from the abbey during the Dissolution of the Monasteries a thousand years later.

David's life and teachings have inspired a choral work by Welsh Composer Karl Jenkins, Dewi Sant. It is a seven-movement work best known for the classical crossover series Adiemus, which intersperses movements reflecting the themes of David's last sermon with those drawing from three Psalms. An oratorio by another Welsh Composer Arwel Hughes, also entitled Dewi Sant, was composed in 1950.

In the 2004 edition of the Roman Martyrology, David is listed under 1 March with the Latin name Dávus. He is recognised as bishop of Menevia in Wales who governed his monastery following the Example of the Eastern Fathers. Through his leadership, many monks went forth to evangelise Wales, Ireland, Cornwall and Armorica (Brittany and surrounding provinces).

Many of the traditional tales about David are found in the Buchedd Dewi ("Life of David"), a hagiography written by Rhygyfarch in the late 11th century. Rhygyfarch claimed it was based on documents found in the cathedral archives. Modern historians are sceptical of some of its claims: one of Rhygyfarch's aims was to establish some independence for the Welsh church, which had refused the Roman rite until the 8th century and now sought a metropolitan status equal to that of Canterbury. (This may apply to the supposed pilgrimage to Jerusalem where he is said to have been anointed as an archbishop by the patriarch).

The restored Shrine of Saint David was unveiled and rededicated by the Right Reverend Wyn Evans, Bishop of St David's, at a Choral Eucharist on Saint David's Day, 2012.