Llanynys (Welsh: [ɬanˈənɪs]) is a hamlet and community (Llanynys and Rhewl Community Council)[1] in Denbighshire, north-east Wales; (OS grid reference: SJ1062).

It lies in the Vale of Clwyd, a few miles north of Ruthin, and includes the village of Rhewl.

It is situated on a small rise between the winding Clwyd and Clywedog rivers, hence the name ynys (island).

South of the village, on the Ruthin to Denbigh road, stands Bachymbyd Fawr, an ancestral home of the Salusbury family.

Prominent landowners and politicians in the 16th and 17th centuries, the Salesburys served as members of parliament for Denbighshire and Denbigh Boroughs and as High Sheriffs for the county.