Assington is four miles (6.4 km) south-east of Sudbury.

At the 2011 Census it had a population of 402. The parish includes the hamlets of Rose Green and Dorking Tye.

According to Eilert Ekwall the meaning of the name is "homestead of Assi". The village was mentioned in the Domesday Book when it had a 78 households. At the survey in 1086 it was held by Ranulf Peverel. Before the Norman Conquest the village was held by Siward Barn.

The parish church is dedicated to St Edmund the Martyr and dates from the 15th century. It is built from flint and dressed stone. The church was restored in the 19th century.  Six bells hang in the tower with the largest weighing approximately 10cwt (508 kg). The bells, cast and rehung in 1890 by John Warner, were unringable as of 2013.

Assington Hall, which is adjacent to the church, was home of the Gurdon family for many centuries. John Gurdon (c. 1544–1623) was elected the Member of Parliament for the borough of Sudbury in 1571, as was his son Brampton Gurdon (died 1648) in 1621, who became High Sheriff of Suffolk in 1629. Later members of the family were involved in local charities through the 18th century.