William Williams, Pantycelyn, also known as William Williams, Williams Pantycelyn, and Pantycelyn, was generally seen as Wales's premier hymnist. He is also rated among the great literary figures of Wales, as a writer of poetry and prose. In religion he was among the leaders of the 18th-century Welsh Methodist revival, along with the evangelists Howell Harris and Daniel Rowland.

The Welsh Methodist revival was an evangelical revival that revitalised Christianity in Wales during the 18th century. Methodist preachers such as Daniel Rowland, William Williams and Howell Harris were heavily influential in the movement. The revival led eventually to the establishment of the Welsh Calvinistic Methodists as a denomination and it also revitalised older dissenting churches.