Grefrath (German pronunciation: [ˈɡʁeːfʁaːt]) is a municipality in the district of Viersen, in the western part of North Rhine-Westphalia, Germany.

It is situated in the Lower Rhineland region (German: Niederhein), which is located between the river Rhine and the borderline between Germany and the Netherlands.

Following the conclusion of the Treaty of Utrecht in 1713, the Spanish part of the duchy of Geldern was added to Prussia.

Over a century later, when the country of Prussia was finally dissolved, Grefrath became a part of the newly created German federal state of North Rhine-Westphalia.

These teams were responsible for the security and maintenance of the Nike Hercules missile and was the only nuclear-armed surface-to-air weapon operational with the US Army.