Ethylene–norbornene copolymers are a significant kind of cyclic olefin copolymer (COC) produced by vinyl-type coordination copolymerization of ethylene and norbornene catalyzed by transition metal catalysts. These totally amorphous copolymers are strong, stiff, highly transparent, and colorless. They have a very high moisture barrier and interesting electrical properties. The copolymers became commercially available in 2001, and products can be obtained from manufacturers such as Polyplastics. This article describes the microstructures, properties, manufacturing, processing, and applications of this kind of polymeric materials. A basic background on the general COC materials is provided in the introduction. Then the dependency relationship between the microstructure and property is mainly discussed. The diversified copolymerization systems, including metallocene catalysts and post-metallocene catalysts, for E–NBE copolymers manufacturing have been revealed. The processing and applications of selected commercially available copolymer products are also summarized.