Saint Helier Harbour is the main harbour on the Channel Island of Jersey. It is on the south coast of the island, occupying most of the coast of the main town of St Helier. It is operated by Ports of Jersey, a company wholly owned by the Government of Jersey.

Facilities include three marinas for berthing private yachts on pontoons, drying harbours and facilities for commercial shipping including roll-on/roll-off ferry berths, a tanker berth and a dock for lift-on/lift-off cargo ships.

Saint Helier Harbour is named after Helier (or Helerius), a 6th-century ascetic hermit from Belgium. The traditional date of his martyrdom is AD 555. His feast day, marked by an annual municipal and ecumenical pilgrimage to the Hermitage, is on 16 July.

The medieval hagiographies of Helier, the patron saint martyred in Jersey and after whom the parish and town are named, suggest a picture of a small fishing village on the dunes between the marshy land behind and the high-water mark.

An Abbey of Saint Helier was founded in 1155 on L'Islet, a tidal island adjacent to the Hermitage. Closed at the Reformation, the site of the abbey was fortified to create the castle that replaced Mont Orgueil as the island's major fortress. The new Elizabeth Castle was named after the Queen by the Governor of Jersey 1600–1603, Sir Walter Raleigh.

The harbour was constructed in the early 19th century. Previously, ships coming into the town had only a small jetty at the site now called the English Harbour and the French Harbour. The Chamber of Commerce urged the States Assembly to build a new harbour, but they refused, so the Chamber took it into their own hands and paid to upgrade the harbour in 1790. A new breakwater was constructed to shelter the jetty and harbours. In 1814, the merchants constructed the roads now known as Commercial Buildings and Le Quai des Marchands to connect the harbours to the town and in 1832 construction was finished on the Esplanade and its sea wall. A rapid expansion in shipping led the States of Jersey in 1837 to order the construction of two new piers: the Victoria and Albert Piers.

The main harbour provides deep water berths for commercial vessels alongside the Victoria Quay and New North Quay.

The Elizabeth Harbour consists of a ferry terminal, two roll-on/roll-off ferry berths and a trailer park for shipping containers. These are used by high-speed craft to Poole, Guernsey and Saint-Malo, traditional ferries to Saint-Malo, Guernsey and Portsmouth and foot passenger ferries to Granville, Barneville-Carteret and Sark.

There are three marinas — the La Collette Yacht Basin, the Saint Helier Marina (built in 1980) and the Elizabeth Marina. The La Collette Yacht Basin is the only one of these to provide non-tidal, 24-hour access to the sea and is home to Jersey's commercial fishing fleet.

Since 2008, Saint Helier Marina has been the venue for the annual Jersey Boat Show.

The Old Harbour, English Harbour and French Harbour have berths for over 500 motorboats and sailing yachts which dry out on the mud at low tide.

• Condor Ferries
• Jersey Airport
• Jersey Coastguard
• Jersey Maritime Museum
• Maritime history of the Channel Islands
• Transport in Jersey

• Official website