Blything was a hundred of eastern Suffolk, and with an area of 87,641 acres (354.67 km²) was the largest of Suffolk's 21 hundreds.

The origins of the hundred centre on the ancient royal estate of Blythburgh, whose hall housed the hundred's central meeting place.

Listed as Blidinga in the Domesday Book, the hundred's name means "the people of the Blyth" a subgroup of the Iceni who populated the valleys of the River Blyth; the hundred corresponds closely to the drainage basin of the River Blyth together with other minor rivers. The name "Blyth" itself means 'blithe' or 'pleasant' and shares its name with a river in Northamptonshire, and one in Northumberland.

Blythburgh Hundred Incorpration was created by act of parliament in 1746.

Blything Hundred consisted of the following parishes:

52°20′N 1°32′E / 52.34°N 1.54°E / 52.34; 1.54