Glenveagh Deer Forest, Forest reserve in County Donegal, Ireland.

Glenveagh Deer Forest is a forest area in County Donegal, Ulster, about 220 km north-west of Dublin, lying on the shore of Lough Beagh. The terrain is woodland and open ground under a coastal climate with mild, wet weather: February averages about 1 °C and July about 12 °C.

Glenveagh Castle was built between 1867 and 1873 for John George Adair, a Donegal-born landowner who had made his fortune in the United States. He modelled the granite tower house on Balmoral, and his wife Cornelia later laid out the gardens. The estate passed to the McIlhenny family in 1937 and to the Irish state in 1983.

Locals remember John George Adair's evictions of tenant families from the Glenveagh estate in 1861, during the famine years, and the district became known as "Adair's Route". The story is still told in Derryveagh and shapes how people speak of the estate today.

The forest lies on the shore of Lough Beagh, about 220 km north-west of Dublin in County Donegal. The climate is coastal, with February averages near 1 °C and July near 12 °C, so walkers should expect cool, damp conditions in any season. Access is by road through Glenveagh National Park.

The forest is home to Ireland's largest red deer population and serves as a reintroduction site for golden eagles, which returned to the area in 2000 after being absent for generations. This return is considered one of the region's major conservation achievements.