Santon Downham is a village and civil parish in the Forest Heath district of Suffolk in eastern England. In 2005 it had a population of 240. The village is located within Thetford Forest on a meander of the River Little Ouse on the Norfolk-Suffolk border.
The village was the administrative centre for HM Forestry Commission for many years following the planting of ten of thousands of trees in the Breckland area to form the Thetford Forest. The District office and staff were housed in 1960s office building close to the site of the now demolished Santon Downham Hall. The Hall garden formed the base for the nursery department of the district. The HM Forestry Commission Repair depot was built close by in an award winning design building, next to which stood the HMFC fire station. A Bedford 'green goddess fire tender and a water tanker were kept in the fire station due to the high fire risk in the area.
The bridge over the River Little Ouse appeared in an episode of Dad's Army when Captain Mainwaring and his troops attempted to demolish the bridge.