The Mayflower Line is the name given to the branch railway line from Manningtree to Harwich in the county of Essex in England. The line diverges from the Great Eastern Main Line at Manningtree. It is double track between Manningtree and Harwich International, and is electrified at 25 kV AC, using overhead wires. East of Manningtree there is a triangular junction so that trains operating to Harwich can reach the branch from both north and south directions.
Stations on the line are:
- Harwich International
- Harwich Town
Passenger services are currently operated by 'one'. They replaced the previous operator, First Great Eastern, on 1 April 2004, when all the operators in East Anglia were merged into one new franchise. Services are formed using Class 321 or Class 360 electrical multiple units.