Llanarmon-yn-Iâl is a village, and local government community, in Denbighshire, Wales, lying in limestone country in the valley of the River Alyn.

The village sits on the B5431 road, near the junction with the B5430, six miles south of the market town of Mold, at approximate Ordnance Survey map grid reference SJ190562.

The village, considered the capital of the commote of Iâl (Yale)—the "hill country"—grew up around a religious community dedicated to a Roman Bishop named St. Germanus of Auxerre (St. Garmon in the Welsh language).

Near to the village, the Lords of Yale had constructed an earth-and-timber motte and bailey castle, Tomen-y-faerdre, during the 11th century, which seems to have acted as an administrative centre.

In the 19th century it was one of the few places in north Wales where wheat was grown, through heavy treatment of the fields with lime, which also helped to create lush pasture for the drovers' cattle.