Greysteel or Gresteel is a village in County Londonderry, Northern Ireland. It lies 9 miles (14 km) to the east of Derry and 7 miles (11 km) to the west of Limavady on the main A2 coast road between Limavady and Derry, overlooking Lough Foyle. It is designated as a Large Village and in the 2001 Census it had a population of 1,229 people, an increase of almost 20% compared to 1991.

The village lies mostly within the townlands of Gresteel More and Gresteel Beg. Historically these townlands were called Craisteele or Glasteele. The origin of Craisteele is uncertain, but Glasteele may be from Irish: Glas-stiall meaning "green strip". The Placenames Database of Ireland lists Glas-stiall as the Irish name of the village.

The Greysteel massacre took place on 30 October 1993 when three members of the Ulster Freedom Fighters attacked a crowded bar with firearms, killing eight people. This was the only fatal incident of "the Troubles" to occur in or near Greysteel.

Until relatively recently, the village had limited local facilities, with a modest sized general shop, a few other retail units, a primary school, a Gaelic club with playing fields and several public houses. However, the recent construction of the Vale Centre, developed by Greysteel Community Enterprise, a local development group, includes a range of commercial/industrial units and playing fields and has improved the situation. A range of activities is available in the Centre, including an after school club, adult learning centre and sports facilities. Commercial facilities in the Centre, provide an opportunity for small business start-ups and a further 10 units are currently under construction. The village has grown considerably during the Post War period, mostly through new public sector housing up to the 1970s, and subsequently through considerable private housing development.

Nathan Carter (born July 30, 1983) is a Canadian actor born in Toronto, Canada. He is best known for his starring roles in Radio Free Roscoe as Travis. He has also guest starred on The Famous Jett Jackson and PSI Factor: Chronicles of the Paranormal.