Geordie (/ˈdʒɔːrdi/ JOR-dee) is a demonym and vernacular dialect characterising Newcastle-upon-Tyne and the wider Tyneside area of North East England.

The vernacular, also known as Tyneside English or Newcastle English in linguistics, is one of the major dialects of northern England. It developed as a variety of the old Northumbrian dialect.

As a regional nickname, applying the term is set by one's definition of or acceptance to being called a Geordie: it varies from supporters of Newcastle United Football Club, the city, Tyneside, Tyne-and-Wear and to North East England. People from the latter two wider areas are less likely to accept the term as applying to them.

The term has also been applied to the Geordie Schooner, glass traditionally used to serve Newcastle Brown Ale. It is often considered unintelligible to many other native English speakers. The Geordie dialect and identity are perceived as the "most attractive in England", according to a 2008 newspaper survey, amongst the British public and as working-class.

Like all English dialects, the Geordie dialect traces back to the Old English spoken by Anglo-Saxon settlers, initially employed by the ancient Brythons who fought Pictish invaders after the end of Roman rule in Britain in the 5th century. The Angles, Saxons, and Jutes who arrived became ascendant politically and culturally over the native British through subsequent migration from tribal homelands along the North Sea coast of mainland Europe. The Anglo-Saxon kingdoms that emerged in the Dark Ages spoke largely mutually intelligible varieties of what is now called Old English, each varying somewhat in phonology, morphology, syntax, and lexicon. In Northern England and the Scottish borders, then dominated by the kingdom of Northumbria, there developed a distinct Northumbrian Old English dialect, which preceded modern Geordie. The linguistic conservatism of Geordie means that poems by the Anglo-Saxon scholar the Venerable Bede can be translated more successfully into Geordie than into standard modern English.

The British Library points out that the Norse, who primarily lived south of the River Tees, affected the language in Yorkshire but not in regions to the north. This source adds that "the border skirmishes that broke out sporadically during the Middle Ages meant the River Tweed established itself as a significant northern barrier against Scottish influence". Today, many who speak the Geordie dialect use words such as gan ('go' – modern Dutch gaan) and bairn ('child' – modern Danish barn), which "can still trace their roots right back to the Angles".

When referring to the people, as opposed to the dialect, dictionary definitions of a Geordie typically refer to a native or inhabitant of Newcastle upon Tyne, England, or its environs, an area that encompasses North Tyneside, Newcastle, South Tyneside and Gateshead. This area has a combined population of around 700,000, based on 2011 census-data.

The term itself, according to Brockett, originated from all the North East coal mines. The catchment area for the term "Geordie" can include Northumberland and County Durham or be confined to an area as small as the city of Newcastle upon Tyne and the metropolitan boroughs of Tyneside.