Llantysilio Welsh: Llandysilio-yn-Iâl
Valle Crucis Abbey
Llantysilio Location within Denbighshire
Population	421 (2011)
OS grid reference	SJ1943
Community	Llantysilio
Principal area	Denbighshire
Preserved county	Clwyd
Country	Wales
Sovereign state	United Kingdom
Post town	LLANGOLLEN
Postcode district	LL20
Dialling code	01978
Police	North Wales
Fire	North Wales
Ambulance	Welsh
UK Parliament	Clwyd South
Senedd Cymru – Welsh Parliament	Clwyd South
List of places UK Wales Denbighshire 52°58′59″N 3°12′11″W / 52.983°N 3.203°W / 52.983; -3.203

Llantysilio (Welsh: Llandysilio-yn-Iâl) is a community in Denbighshire, Wales, near Llangollen. It has a population of 472,^[1] falling to 421 at the 2011 census.^[2]

The community includes the site of Valle Crucis Abbey, the Horseshoe Pass, and Llantysilio Hall; it also includes the villages of Pentredwr and Rhewl, as well as the areas of Eglwyseg, Llandynan, and Llidiart Annie.^[3]