Southampton has been a centre for shipping and trade for centuries. Watergate Quay is first recorded in 1411. It stood at the foot of the High Street on the site of today's Town Quay, and it was bordered by the town walls. Small wharves extended either side of Watergate Quay. To the east they reached 'the platform', an area built in the 13th century area for defence of the town, and on towards the oyster beds where the Eastern Docks lie today. Faced with competition from London, continental trade from Southampton declined after 1700, leaving Watergate Quay derelict.

In 1803 the newly-formed Harbour Commissioners demolished Watergate and began to build the new Town Quay on the site. The Royal Pier was opened in 1833 (the first jetty or pier in Southampton). It was used by steamers to the Channel Islands, Le Havre and the Isle of Wight. In 1853, a jetty was built at Town Quay. A new Customs House had also been built on the Town Quay in 1847.

The London & South Western Railway (LSWR) arrived in 1840, linking London to Southampton Terminus Station (although not officially named as such until 1923), less than a mile from the Royal Pier. Two years earlier, the Southampton Dock Company had started on the construction of the first dock, the Outer Dock, later part of the Eastern Docks system. The Outer Dock opened in 1842, the first ships to use it being the P&O liners Tagus and Liverpool. The continental steamers moved to the Outer Dock once the railway arrived. The first three drydocks at Southampton were built between 1846 and 1854, able to take the largest ships of the day. The Inner Dock was opened in 1851. It was connected to the Outer Dock by locks, and was the only closed wet dock in Southampton.

Trade grew rapidly and 2000 feet of quays were built on the River Itchen, completed in 1876. Three years later, a fourth drydock was opened, mainly for use by the Union SS Co. In 1890, the larger Empress Dock was opened by Queen Victoria. This was largely financed by loans from the LSWR, since the Southampton Dock Co was in a poor financial position. The largest vessels of the day could enter or leave at any state of the tide, the only port in the UK which could claim this. The Dock Company finances did not improve, and so the LSWR bought the docks in 1892 for £1,360,000. Further Quays were added on the Itchen, these being completed in 1895, and the Prince of Wales drydock, the largest in the world at the time, opened the same year.

The White Star Line transferred its express services from Liverpool to Southampton in 1907, and the White Star Dock was built to accommodate them. When Cunard and Canadian Pacific followed suit after the First War, the dock was renamed the Ocean Dock. The docks were controlled by the Government during the First War, and afterwards returned to the LSWR, who continued their expansion. The LSWR passed to the Southern Railway in 1923. The Southern Railway began work on a massive construction project to create a 7000 foot quay west of the Royal Pier. This became the New Docks (later Western Docks), and the fist ship to visit was Cunard's Mauritania in 1932. The 1200 foot King George V drydock was also part of the scheme, first used by the White Star's Majestic in 1934. In the same year, Imperial Airways began using Southampton for their flying boats on services around the Empire.

Southampton was again extremely busy during the Second War, and remained so after peace returned. The famous Ocean Terminal was opened alongside the Ocean Dock in 1950. New passenger liners regularly entered service until the 1960s, but by the end of this decade travel patterns had changed radically, with most people travelling by air. The Ocean Terminal was closed in 1980 and demolished three years later. The railway passenger ferry services ceased in 1964, but the first ro-ro car ferry service was started by Thoresen Car Ferries in the same year, with a car ferry berth in the Outer Dock. The Inner Dock was filled in to provide car storage areas for this service, and other services started by Swedish Lloyd and Southern Ferries (later Normandy Ferries, then P&O). By 1984, all these services had either closed or moved to Portsmouth. The Queen Elizabeth II passenger terminal was opened in 1966, and remains in regular use for Cunard and other cruise ships. In 1967 the Outer Dock was renamed the Princess Alexandria Dock. It remains as the marina for the Ocean Village.

Southampton had always been primarily a passenger port, although most ships carried substantial amounts of cargo too. With the decline of the passenger liners, this emphasis was about to change, with the opening of the first 900 foot container berth in 1968. It was soon joined by a second of the same size, plus a further 3900 feet in the 1970s. Southampton is also a major importer and exporter of cars, with at least one of the ugly car-carriers in port at any time. In more recent times, passengers have regained their importance, this time for people taking cruises. Whilst never looking as busy as in previous times (cruise ships turn around in a day whereas passenger liners spent a considerable time dealing with cargo), four large cruise ships were in port simultaneously on a number of days in 2006, and their combined gross tonnage probably exceeds that of all the ships in port on busy days in the 1950s.

A temporary terminus for the LSWR line from Winchester to Southampton was opened at Southampton Northam Road on 10th June 1839, this was made necessary because of a dispute over the crossing at Northam Road. The new terminus was eventually opened the following year. The station was opened as Southampton being renamed Southampton Docks in July 1858, Southampton Town and Docks in September 1896 and Southampton Town for Docks in November 1912. It was finally renamed Southampton Terminus on 9th July 1923.

This fine Italianate building was designed by Sir William Tite and included a train shed and six platforms. Some tracks running through the station to the docks are still maintained and used by regular but infrequent Pullman services meeting cruise ships, and even more occasional mail and freight trains. Southampton's main railway station is now Southampton Central. It closed in 1966 and was re-named South Western House. Home to BBC South for a number of years it is presently a casino. It is listed Grade II *.