NGK Spark Plugs Co., Ltd. is a public company established in 1936 and based in Nagoya, Japan. NGK manufactures and sells spark plugs and related products for internal combustion engines, along with ceramics and applicable products.

As of March 2007, the company employed 10,407 people, and operated a network of 7 liaison offices, 12 sales offices, 13 production sites and 2 technical centers worldwide. NGK Spark Plugs was founded as a spin-off of the spark plug division of NGK Insulators. Originally, NGK supplied most of its products to Japanese automakers. Today the company is the largest OEM sparkplug maker in the world.