Harwich International Port is a North Sea seaport in Essex, England. It is on the south bank of the River Stour which is one mile upstream from the tower of Harwich. The port was known as Parkeston Quay. It is one of the UKs most important deep water harbours.

The Great Eastern Railway and the Eastern Union Railway operated passenger steamers across the North Sea from Harwich to Europe in 1862. In 1872 shipping trade had increased so that more capacity was needed and the Great Eastern Railway obtained permission to reclaim land at Ray Farm and build a new quay. Ray Farm is a mile to the west of Harwich. The new quay was opened in 1883, and named Parkeston Quay. The port has its own railway station and a hotel, which was built between the northern platform and the quay. The hotel is now used as offices. The railway station was originally called Parkeston, then Parkeston Quay and is currently called Harwich International.

The port stayed under the ownership of the Great Eastern Railway until 1923 when the company became part of the London and North Eastern Railway. In 1939 the Admiralty requisitioned Parkeston Quay for naval purposes and named it HMS Badger and released it back to the London and North Eastern Railway in 1946. In January 1948 the London and North Eastern Railway was nationalised and the port became under the ownership of British Railways and was sold to sea containers in 1984. It was sold to Stena Line 1989. In 1997 Parkeston Quay was acquired by Hutchison Ports (UK) Ltd who are the current owners and have renamed the port Harwich International Port.

The port is mainly involved with ferry operations with regular sailings to Rotterndam/Europort, Hook of Holland and Esbjerg. The Harwich-Cuxhaven route was discontinued in 2005. Cruise ships regularly call at the port during the summer months. Tankers call at the Petrochem Carless refinery and general cargo and bulk cargos are worked at the port.

The port is currently the base for the installation of offshire wind farms in the southern North Sea.

The port has four roll-on roll-off with linkspans. The specialised pier for the High Speed Ferry Stena Discovery is disused. There are extensive railway sidings adjacent to and within the port with 40 acres of standing for cars and there is over 105 acres of operational land with parking for over 1000 trailers.