Coordinates: 54°53′31″N 7°01′52″W / 54.892°N 7.031°W
Banagher (pronounced /ˈbænəhər/ BAN-ə-hər, from Irish: Beannchar) is a parish in County Londonderry, Northern Ireland. The parish is made up of the medieval parish of Banagher and parts of the ancient parish of Boveva and the townland of Tireighter and Park, once in the parish of Cumber. Banagher has many ancient monuments, including churches, holy wells, standing stones and chambered graves.
Banagher lies in the western foothills of the Sperrin Mountains, between the rivers Roe and Faughan. The landscape is mostly rugged, with glens and narrow valleys rising into the highlands. Banagher Glen is a good example of the area's terrain and forms an important conservation area, preserving one of the few surviving examples of old-growth deciduous woodland in Ireland. The Glen has a trail which climbs through the woods to Altnaheglish Dam and Reservoir, which supplies water to Derry. The path up to the dam from the valley floor climbs through deciduous woodland and higher coniferous woodland to moor and heathland.