Ulster Protestants are an ethnoreligious group in the Irish province of Ulster, where they make up about 43.5% of the population. Most Ulster Protestants are descendants of settlers who arrived from Britain in the early 17th century Ulster Plantation. This was the settlement of the Gaelic, Catholic province of Ulster by Scots and English speaking Protestants, mostly from the Scottish Lowlands and Northern England. Many more Scottish Protestant migrants arrived in Ulster in the late 17th century. Those who came from Scotland were mostly Presbyterians, while those from England were mostly Anglicans. There is also a small Methodist community and the Methodist Church in Ireland dates to John Wesley's visit to Ulster in 1752. Although most Ulster Protestants descend from Lowland Scottish people, many descend from English, and to a lesser extent, from Irish, Welsh and Huguenots.

Ulster is one of the four traditional or historic Irish provinces. It is made up of nine counties: six of these constitute Northern Ireland ; the remaining three are in the Republic of Ireland.