Shenfield railway station is on the Great Eastern Main Line in the East of England, serving the village of Shenfield, Essex. As well as being a key interchange for medium- and long-distance services on the main line, it is also the western terminus of a branch line to Southend Victoria and one of the two eastern termini of the Elizabeth line. It is 20 miles 16 chains (32.51 km) down the line from Liverpool Street and is situated between Brentwood and either Ingatestone on the main line or Billericay on the branch line. Its three-letter station code is SNF.

The Great Eastern Main Line is a 114.5-mile (184.3 km) major railway line on the British railway system which connects Liverpool Street station in central London with destinations in east London and the East of England, including Shenfield, Chelmsford, Colchester, Ipswich and Norwich. Its numerous branches also connect the main line to Southminster, Braintree, Sudbury, Harwich and a number of coastal towns including Southend-on-Sea, Clacton-on-Sea, Walton-on-the-Naze and Lowestoft.