Suffolk is an East Anglian county of historic origin. It has borders with Norfolk to the north, Cambridgeshire to the west and Essex to the south. The North Sea lies to the east. The county town is Ipswich; other important towns include Lowestoft, Bury St Edmunds and Felixstowe, one of the largest container ports in Europe.

Much of Suffolk is low-lying, founded on Pleistocene sand and clays. These rocks are relatively unresistant and the coast is eroding rapidly. Coastal defences have been used to protect several towns, but several cliff-top houses have been lost to coastal erosion in the past, and others are under threat. The continuing protection of the coastline and the estuaries, including the Blyth, Alde and Deben, has been, and remains, a matter of considerable discussion.

The coastal strip to the East contains an area of heathland known as "The Sandlings" which runs almost the full length of the coastline. Suffolk is also home to nature reserves, such as the Trimley Marshes, a wetland under the protection of Suffolk Wildlife Trust.

The west of the county lies on more resistant Cretaceous chalk. This chalk is responsible for a sweeping tract of largely downland landscapes that stretch from Dorset in the south west to Dover in the south east and north through East Anglia to the Yorkshire Wolds. The chalk is less easily eroded so forms the only significant hills in the county. The highest point of the county is Great Wood Hill, the highest point of the Newmarket Ridge, near the village of Rede which reaches 128 metres (420 ft).

The county flower of the county of Suffolk is the oxlip.