Marks Tey railway station is on the Great Eastern Main Line (GEML) in the East of England, serving the large village of Marks Tey, Essex. It is 46 miles 49 chains (75.02 km) down the line from London Liverpool Street and on the GEML is situated between Kelvedon to the west and Colchester to the east. Marks Tey is also the southern terminus of the Gainsborough Line to Sudbury. Its three-letter station code is MKT. The "up" (London-bound) platform 1 has an operational length for nine-coach trains, the "down" (Colchester-bound) platform 2 can accommodate 11-coach trains and platform 3 has an operational length for two-coach trains.

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.