Debenham Parish is situated 11½ miles north Ipswich and consists of 3,271 acres in the administrative area of Mid Suffolk District Council. It is one of the five parishes that also include Ashfield, Framsden, Pettaugh, and Winston, which together comprise the Thredling Hundred.
An extensive plateau of 200 feet is penetrated in the Debenham area by the shallow valleys of four streams which unite to form the River Deben and to the sea at Felixstowe. The river was recorded as navigable to Debenham, but is now passable to Woodbridge, 8 miles from its mouth.
The surrounding soil, apart from near the streams, is a heavy moisture retaining marl-clay overlying chalk. Arable farming forms the backbone of the region's industry with crops consisting of Barley, Flux, Rape Seed, Root Vegetables including Sugar Beet and Wheat.
Records indicate that the population for Debenham in 1801 was 1,215; rising to 1,629 in 1831, but by 1901 had reduced to 1,182. The resident population of Debenham, as measured in the 2001 Census, was 2,076 residing in 878 households of which 47 per cent were male and 53 per cent were female. The resident population of Mid Suffolk was 86,837, of which 50 per cent were male and 50 per cent were female.