Saint Winefride (also: Saint Winifred, Gwenfrewi, Saint Gwenfrewy, Guinevere, Winfred of Wales) was a 7th century Welsh woman who had her head severed from her body by an enraged suitor, Caradog. He was displeased because her religious devotion and a pledge to become a nun caused her to resist his advances.

In one version of this tale, her head rolled downhill, and, where it stopped, a healing spring appeared. These healing waters are now a shrine called St Winefride's Well in Holywell, the Lourdes of Wales. St. Winefride's head was subsequently rejoined to her body due to the efforts of a relative, Saint Beuno, and she was restored to life. She later became a nun and abbess at Gwytherin in Denbighshire, after Caradog, cursed by Beuno, melted into the ground. More elaborate versions of this tale relate many details of her life, including Winifred's pilgrimage to Rome.

In spite of the slim records for this period, there appears to be a historical basis for this personage. Winifred's brother Owain is known to have killed Caradog as revenge for a crime. She succeeded the Abbess, Saint Tenoi, who is believed to be her aunt.

After her death (c. 660) she was interred at her abbey. In 1138 relics were carried to Shrewsbury to form the basis of an elaborate shrine (An event woven into one of Ellis Peters' Brother Cadfael stories, A Morbid Taste for Bones). The shrine and well became major pilgrimage goals in the late Middle Ages, but the shrine was destroyed by Henry VIII in 1540.