Eastern United Colliery was a drift mine in the Forest of Dean, Gloucestershire, England served by the Great Western Railway's Forest of Dean Branch.
The colliery was one of the seven areas of deep gales - founded after the Dean Forest (Mines) Act in 1904.
The colliery exploited six seams containing 41,000,000 long tons (41,700,000 t) of coal which could give a working life of around 200 years (at an extraction rate of 200,000 long tons (203,000 t) per annum.[1] The principal coal seam was the Coleford High Delf, a steam coal much in demand and said to be up to 5 ft 0 in (1.524 m) thick. Demand led to discussions with the Great Western Railway over the provision of a link to its network.[2]