Cristiolus

{{Short description|6th-century Welsh saint}}

{{Use dmy dates|date=June 2023}}

File:Parish Church, Eglwyswrw, view from southeast - geograph.org.uk - 786705.jpg ]]

Cristiolus was a Welsh saint who lived in the 6th century.

According to tradition, he was a son of Hywel,{{cite journal | title = Genealogy of the Saints (Continued) | journal = The Cambro-Briton | volume = 3 | issue = 24 | pages = 84 | date = 1821 | jstor = 30069046}} son of Emyr Llydaw and therefore brother to Saint Sulien, Saint Rhystud and Derfel Firm, and perhaps also Dwywe (or Dwywau).

There are churches dedicated to Cristiolus at Llangristiolus, Anglesey, together with Eglwyswrw and Penrhydd (Pembrokeshire). He is commemorated on 3 November.{{Cite web|url=http://celticsaints.org/2008/200811.html|title=Celtic and Old English Saints - November 2008|website=celticsaints.org}}