Портси — остров-город у южного побережья Англии.

Island off the southern coast of England
the town in Australia

Portsea Island is a flat and low lying natural island in area, just off the southern coast of Hampshire in England. Portsea Island contains the majority of the city of Portsmouth. Portsea Island has the third largest population of all the islands in the British Isles after the mainlands of Great Britain and Ireland; it also has the highest population density of any British Isle, and Portsmouth has the highest population density of any city in the UK outside of London. To the east of Portsea Island lies Hayling Island, separated by Langstone Harbour. To the west is the peninsular mainland town of Gosport, separated by Portsmouth Harbour. To the south, it faces into the Spithead area of the wider Solent. A narrow tidal channel along the northern edge of Portsea Island, known as Portsea Creek, separates Portsea Island from the mainland. Three roads connect Portsea Island to the mainland road network; the M275 motorway, the A3 London Road (split on two separate bridges) and the A2030 Eastern Road. There are also two pedestrian and bicycle bridges over Portsea Creek. In Portsmouth Harbour, a road bridge connects Portsea Island to Whale Island, a restricted Royal Navy shore base establishment. Portsea Island has four railway stations (Portsmouth Harbour, Portsmouth & Southsea, Fratton and Hilsea) connected by an island branch line to the mainland railway network via a short railway bridge over Portsea Creek. In addition there are ferry services to Gosport (on the mainland), Hayling Island and the Isle of Wight. There are also ferries to the Channel Islands, northern France and northern Spain. Portsea Island gives its name to a neighbourhood of Portsmouth historically known as The Common, now formally known as Portsea and also the Portsea Parish of the island.

Portsea's name is derived from the Latin word portus, meaning harbour and the Saxon word eg (pronounced 'ee'), or ea (pronounced 'ee') meaning island. Portsea Island was previously named with a Latin Saxon Portus eg (or Portuseg) name (alternatively Portus ea or Portusea). Local people began adding the additional Island noun after the Portuseg (or Portusea) name in later times after the Saxon eg and ea meaning had become lost.

Two Bronze Age hoards and a hoard of Roman coins have been found on the island. In 979 AD the island was raided by Danes. At the time of the Domesday Book, three manors were recorded as being on the island.

Adjoining the eastern green belt, this extends into the heart of the Baffins neighbourhood which has a large pond and the grounds of Portsmouth College.

Buckland is a central neighbourhood at the heart of the island, directly north of Kingston and north east of Landport.

Copnor is an area on the eastern side of Portsea Island. As Copenore, it was one of the three villages listed as being on Portsea Island in the Domesday book. In the late 19th and early 20th century the rapid expansion of Portsmouth saw the original village engulfed. The west of the district is now a predominantly residential area of 1930s housing, while the east is an industrial and commercial area. It was originally intended to have a railway station; the intermediate station between Havant and Portsmouth Town stations when the line opened. However, this never materialised, in spite of the large gap between stations, and the existence of a signalled level crossing for many years (now a bridge). A "Station Road" was laid out, and still exists, however construction on the station never began.

Fronting the beach along the southern shore is the promenade road of Eastney, which includes is punctuated by three forts, small Eastney Fort West (dismantled), Eastney Fort East and large Fort Cumberland, which occupies a modest peninsula. Eastney is the most south eastern area of Portsea island and forms part of the entrance into Langstone Harbour. Eastney offers a marina (confusingly named as "Southsea Marina") and also a foot passenger ferry service across Langstone Harbour to neighbouring Hayling Island. Eastney Lake, a natural tidal inlet of Langstone Harbour is located on the northern side of the Eastney peninsular, with Milton on the opposite northern side of Eastney Lake. A small enclosed lagoon nicknamed 'The Glory Hole' is located on the southern side of Eastney Lake, and is refilled with Langstone Harbour's salt water on high spring tides. Eastney Lake is also known by locals as 'Eastney Creek' or 'The Creek'.

Fratton is a residential and light industrial area of Portsmouth. It consists mostly of Victorian terraced houses, and is typical of the residential areas in the city. There is also a modest shopping centre on Fratton Road, The Bridge Centre, built on the site of a large former Co op department store, now dominated by a large Asda supermarket, which reflects the working class naval and industrial heritage of the Fratton district, with localised rather than centralised low budget shops and cafés. Fratton railway station is one of four stations remaining on Portsea Island and forms part of the Portsmouth Direct line. To the east of Fratton railway station there is Fratton Traincare Depot, a train maintenance depot. The large former Fratton railway goods yard was cleared in the late 1990s and early 2000s, making way for a retail park.

Hilsea is the north western district of the city, with a mixture of residential and industrial/retail/distribution areas. It is home to one of Portsmouth's main sports and leisure facilities, the Mountbatten Centre and Trafalgar School. Among its small green belt to the north and west is Portsmouth rugby football club. Anchorage Park is a 1980s housing development which occupies the north eastern portion of Hilsea. Anchorage Park was formerly the location of Portsmouth Airport, Hilsea which was closed in 1973.

This small central, typical, terraced district of the city has a few high rise developments and is entirely residential.

Residential parts of Landport are separated from its trade and distribution premises alongside its Albert Johnson Quay by the M275/A3 where the roads change designation. In the westernmost street of this residential side is a large old listed horse trough and row of listed four homes, the Charles Dickens Birthplace Museum in his birthplace home, and Mile End Chapel (a studio). A section of the original main Portsmouth to London A3 road between Commercial Road, Landport and Kingston Crescent is locally known as Mile End Road area. Landport is also home to the former Mile End House School, which was a boys preparatory school founded by George Lewin Oliver, who later became a founding director of Portsmouth Football Club on 5 April 1898 and club chairman on 27 July 1912.

Rudmore is the name of a former residential district on the western side of Portsea Island near to the naval base and the present day Portsmouth International Port. Rudmore was heavily bombed during World War II and was reduced to rubble. After the war, Rudmore was cleared to make way for the M275 motorway spur and the intersection junction now known as the "Rudmore Roundabout".

Somerstown is an inner city residential district of Portsmouth that was first founded in the early nineteenth century on land owned by a Mr. Somers, in whose name the district is now named.

Southsea occupies the southern end of Portsea Island, within a mile (1.6 km) of Portsmouth's city centre and Portsmouth Harbour. Originally named Croxton Town after the land owner, a Mr. Croxton, Southsea grew into a popular Victorian seaside resort in the nineteenth century. Southsea has a thriving commercial area with well known high street chains, and numerous independent traders which includes restaurants, bars, charity shops, food retailers and furniture/household goods shops. From 1999, Southsea had its own separate town council, but was reintegrated back into Portsmouth City Council in 2010. From 1885, Southsea had its own railway branch line, named the Southsea Railway. The Southsea Railway incorporated three stations at Jessie Road Bridge Halt, Albert Road Bridge Halt and a terminus station called East Southsea at Granada Road. The railway line ran south off a branch line from Fratton Station. The Southsea Railway was closed in 1914 due to economic competition from trams. Railway track and stations were subsequently removed and replaced with roads and housing. On a modern map of Portsmouth, the route of the Southsea Railway can still clearly be seen from the arrangement of the newer housing and roads which replaced it.

This residential area of terraced streets includes Alexandra Park, and the Mountbatten Sports Centre. To the north lie Tipner and Hilsea, and to the south are Kingston, Buckland and Commercial Road, the main retail area of the city. Stamshaw is bounded to its west by the M275 motorway and Whale Island, and to the east is North End. The main thoroughfares of Stamshaw, Twyford Avenue and Stamshaw Road, are two axes of a one way traffic system. An eponymous infant and junior school serve it. Its park adjoining the feeder road terminating at the city centre (with motorway status) has large fields and an adventure playground.

This small north west corner has the public parkland point, Tipner Point, and is a mixture of road use, retail/distribution and residential.

Farlington, Drayton, Cosham, Wymering and Paulsgrove (including Port Solent) are suburbs of Portsmouth built on the mainland of Great Britain, not Portsea Island, all sharing the PO6 postcode area.