Some definitions of Ulster Scots may also include Standard English spoken with an Ulster Scots accent. This is a situation like that of Lowland Scots and Scottish Standard English with words pronounced using the Ulster Scots phonemes closest to those of Standard English. Ulster Scots has been influenced by Hiberno-English, particularly Mid-Ulster English, and by Ulster Irish. As a result of the competing influences of English and Scots, varieties of Ulster Scots can be described as "more English" or "more Scots".
The Scots language arrived in Ulster during the early 17th century, when large numbers of Scots speakers arrived from Lowland Scotland during the Hamilton and Montgomery Settlements and the Ulster Plantation. The earliest Scots writing in Ulster dates from that time, and until the late 20th century, written Scots from Ulster was almost identical with that of Scotland. However, since the revival of interest in the Ulster dialects of Scots in Northern Ireland in the 1990s, new orthographies have been created, which, according to Irish language activist Aodán Mac Póilin, seek "to be as different to English (and occasionally Scots) as possible."
While once referred to as Scotch-Irish by several researchers, that has now been superseded by the term Ulster Scots. Speakers usually refer to their vernacular as 'Braid Scots', 'Scotch' or 'the hamely tongue'. Since the 1980s Ullans, a portmanteau neologism popularized by the physician, amateur historian and politician Ian Adamson, merging Ulster and Lallans, the Scots for Lowlands, but also an acronym for “Ulster-Scots language in literature and native speech” and Ulstèr-Scotch, the preferred revivalist parlance, have also been used. Occasionally, the term Hiberno-Scots is used, but it is usually used for the ethnic group rather than the vernacular.
During the middle of the 20th century, the linguist R. J. Gregg established the geographical boundaries of Ulster's Scots-speaking areas based on information gathered from native speakers.
Ulster Scots is spoken in mid and east Antrim, north Down, north-east County Londonderry, and in the fishing villages of the Mourne coast. It is also spoken in the Laggan district and parts of the Finn Valley in east Donegal and in the south of Inishowen in north Donegal.
The 1999 Northern Ireland Life and Times Survey found that 2% of Northern Ireland residents claimed to speak Ulster Scots, which would mean a total speech community of approximately 30,000 in the territory. Other estimates range from 35,000 in Northern Ireland, to an "optimistic" total of 100,000 including the Republic of Ireland (mainly the east of County Donegal). Speaking at a seminar on 9 September 2004, Ian Sloan of the Northern Ireland Department of Culture, Arts and Leisure (DCAL) accepted that the 1999 Northern Ireland Life and Times Survey "did not significantly indicate that unionists or nationalists were relatively any more or less likely to speak Ulster Scots, although in absolute terms there were more unionists who spoke Ulster Scots than nationalists".
In the 2011 census of Northern Ireland, 16,373 people (0.9% of the population) stated that they can speak, read, write and understand Ulster Scots and 140,204 people (8.1% of the population) reported having some ability in Ulster Scots.