Den-noh Coil (Japanese: 電脳コイル, Hepburn: Dennō Koiru, lit. Cyber Coil), also known as Coil – A Circle of Children; is a Japanese science fiction anime television series produced by Madhouse. The series is created, directed and written by Mitsuo Iso, it aired for 26 episodes in Japan on NHK Educational TV between May and December 2007. The story follows a group of children as they use AR glasses to unravel the mysteries of the half real, half Internet city, using a variety of illegal software tools, techniques, and virtual pets to manipulate the digital landscape.

It is a pioneering work that depicts daily life in a world dominated by AR (augmented reality) technology, in which layers created by computer networks are superimposed on the real world. It has received high praise among critics for its fusion of old-fashioned Japanese scenery and urban legends, a modern version of the Japanese folklore Kaidan, with a futuristic worldview, and for its story of children playing in an augmented reality world using a device called "Den-noh Megane" (cyber glasses), as if anticipating the subsequent emergence of smart glasses.

Den-noh Coil has won several awards, including the Grand Prize of the 29th Nihon SF Taisho Award, the Best Media of the 39th Seiun Award, both in 2008, and the Excellence Award at the 11th Japan Media Arts Festival in 2007.