The Great Eastern Railway, which was formed from the merging of the Eastern Counties Railway and the Eastern Union Railway in 1862, operated passenger steamers across the North Sea from Harwich to continental Europe. By 1872, shipping trade had increased so that more capacity was required and the Great Eastern Railway obtained permission to reclaim land at Ray Farm, a mile to the west of Harwich, and build a new quay. This new quay was opened in 1883 by Charles H. Parkes, the Chairman of the Great Eastern Railway company, the port being named after him as Parkeston Quay. The port had its own railway station, and a hotel was built between the northern platform and the quay; the hotel building is now used as offices. The railway station was originally called Parkeston Quay, but was renamed Harwich Parkeston Quay in 1934 when the new Parkeston Quay West station was opened to serve the west end of the quay. It was given its current name, Harwich International, in 1995.

The port remained under the ownership of the Great Eastern Railway until 1923 when the company became part of the London and North Eastern Railway (LNER). In 1939 the Admiralty requisitioned Parkeston Quay for naval purposes, naming it HMS Badger. It was released back to the LNER in 1946.

On 1 January 1948 the LNER was nationalised and the port came under the ownership of British Railways (BR). In 1984, as part of the privatisation of BR’s Sealink ferry services, the port was sold to Sealink’s new owners Sea Containers, which sold it on to Stena Line in 1989. In 1997 Parkeston Quay was acquired by Hutchison Port Holdings, which renamed the port Harwich International Port.

The operations and maintenance base for the Galloper wind farm is housed in the port and is made up of a dedicated pontoon, warehouse and office space