Newport City Council (Welsh: Cyngor Dinas Casnewydd) is the local authority for Newport, one of the principal areas of Wales. Newport has had a council since at least the 14th century, which has been reformed and had its territory enlarged on numerous occasions. Since 1996 it has been a county borough council. In 2002 it changed its name from Newport County Borough Council to Newport City Council when Newport was awarded city status. It consists of 51 councillors, who represent the city's 20 wards. The council is based at Newport Civic Centre. It has been under Labour majority control since 2012.

Newport was an ancient mesne borough, occupying an important position on the Welsh Marches. The town grew up around Newport Castle, which was built early in the 12th century. Giraldus Cambrensis, writing in 1187, calls it Novus Burgus, probably to distinguish it from Caerleon, whose prosperity declined as that of Newport increased. The first lord was Robert Fitzhamon, who died in 1107, and from him the lordship passed to the Earls of Gloucester and Stafford and the Dukes of Buckingham. Hugh le Despenser, who held the lordship for a short time, obtained in 1323 a charter of liberties for the burgesses, granting them freedom from toll throughout England, Ireland and Aquitaine. Hugh, Earl of Stafford granted a further charter in 1385, confirmed by his grandson in 1427, which gave the burgesses the right of self-government and of a merchant gild. On the attainder of the Duke of Buckingham in 1483 the lordship lapsed to the crown, of whom it was held in the 16th and 17th centuries by the Pembrokes, and in the 19th by the Beauforts.

The town was incorporated by Royal Charter of James I in 1623 and confirmed by Charles II in 1685. This created a corporation which consisted of the Mayor of Newport and twelve aldermen who governed the borough and were responsible for law and order. They were assisted by a recorder and two bailiffs. This system of government lasted in essence until the town was reformed as a municipal borough in 1836 under the Municipal Corporations Act 1835. This reconstituted the corporation as an elected borough council, comprising a mayor, aldermen and councillors. The Newport Borough Police was also formed in 1836.

In 1934 the borough was enlarged by taking in parts of the surrounding parishes of St Woolos, Christchurch, Malpas and Bettws.

When elected county councils were established in 1889 under the Local Government Act 1888, Newport was included in the administrative county of Monmouthshire, being governed by Monmouthshire County Council, which chose to base itself in Newport. Just over two years later, on 7 November 1891, Newport was one of the first places to become a county borough (other than those which had been created directly by the 1888 act), making it administratively independent from Monmouthshire County Council.

Newport Civic Centre, designed by architect Thomas Cecil Howitt, was completed in 1964 to serve as the council's headquarters.

Further local government reorganisation in 1974 saw the abolition of county boroughs. Newport became a lower-tier district with borough status. The reformed borough covered a larger area than the former county borough, covering the whole of two former districts and most of a third, which were abolished at the same time:

The enlarged borough had an area of 46,976 acres (19,011 ha), and was governed by both Newport Borough Council and Gwent County Council. In 1996, another wave of local-government reorganisation reverted the council to its previous status of a self-governing county borough, taking over the functions of the abolished Gwent County Council in the area. In 2002 Newport was granted formal city status as part of a contest for the Queen's Golden Jubilee in 2002, in which one Welsh town was eligible to be awarded city status.