Tonnagh Beg is a townland in County Tyrone, Northern Ireland. It is situated in the barony of Clogher and the civil parish of Donacavey and covers an area of 227 acres.[1]
The name derives from the Irish: Tamhnach beag (Little green field or little field).[2]
In 1841 the population of the townland was 101 people (21 houses) and in 1851 it was 76 people (12 houses).[3]
The townland contains Tonnagh Beg bog, a 55.6hectare designated Area of Special Scientific Interest (ASSI). It is a large lowland raised bog, among the best examples in the west of Northern Ireland.[4]