Ulster Scots or Ulster-Scots, also known as Ulster Scotch and Ullans, is the dialect of Scots spoken in parts of Ulster in Northern Ireland and the Republic of Ireland. It is generally considered a dialect or group of dialects of Scots, although groups such as the Ulster-Scots Language Society and Ulster-Scots Academy consider it a language in its own right, and the Ulster-Scots Agency and former Department of Culture, Arts and Leisure have used the term Ulster-Scots language.

Scots is an Anglic language variety in the West Germanic language family, spoken in Scotland and parts of Ulster in the north of Ireland. Most commonly spoken in the Scottish Lowlands, Northern Isles, and northern Ulster, it is sometimes called Lowland Scots to distinguish it from Scottish Gaelic, the Goidelic Celtic language that was historically restricted to most of the Scottish Highlands, the Hebrides, and Galloway after the sixteenth century; or Broad Scots to distinguish it from Scottish Standard English. Modern Scots is a sister language of Modern English, as the two diverged independently from the same source: Early Middle English (1100–1300).