Pen-y-Cefn Pasture (Welsh: Dolydd Pen-y-Cefn) is a Site of Special Scientific Interest in Cilcain, Flintshire, in the preserved county of Clwyd, north Wales. It has been an SSSI since 10 December 1986 as a conservation attempt to protect and preserve the site. Its area is 2.35 hectares. Natural Resources Wales is the body responsible for the site.