Scottish Americans or Scots Americans (Scottish Gaelic: Ameireaganaich Albannach; Scots: Scots-American) are Americans whose ancestry originates wholly or partly in Scotland. Scottish Americans are closely related to Scotch-Irish Americans, descendants of Ulster Scots, and communities emphasize and celebrate a common heritage. The majority of Scotch-Irish Americans originally came from Lowland Scotland and Northern England before migrating to the province of Ulster in Ireland (see Plantation of Ulster) and thence, beginning about five generations later, to North America in large numbers during the eighteenth century. The number of Scottish Americans is believed to be around 25 million, and celebrations of Scottish identity can be seen through Tartan Day parades, Burns Night celebrations, and Tartan Kirking ceremonies.

Significant emigration from Scotland to America began in the 1700s, accelerating after the Jacobite rising of 1745, the steady degradation of clan structures, and the Highland Clearances. Even higher rates of emigration occurred after these times of social upheaval. In the 1920s, Scotland experienced a reduction in total population of 0.8%, totally absorbing the natural population increase of 7.2%: the U.S. and Canada were the most common destinations of these emigrants. Despite emphasis on the struggles and 'forced exile' of Jacobites and Highland clansmen in popular media, Scottish migration was mostly from the Lowland regions and its pressures included poverty and land clearance but also the variety of positive economic opportunities believed to be available.

Ethnically Scottish, but separated for centuries from mainstream society in Scotland where they were known as Tinkers. Some came to Canada after 1850 and to the United States in appreciable numbers after 1880. Over 100 distinct clans have been identified but total numbers not known.

The table shows the ethnic Scottish population in the British colonies from 1700 to 1775. In 1700 the total population of the colonies was 250,888, of whom 223,071 (89%) were white and 3.0% were ethnically Scottish.

Population estimates are as follows.

The number of Americans of Scottish descent today is estimated to be 20 to 25 million (up to 8.3% of the total U.S. population).

The majority of Scotch-Irish Americans originally came from Lowland Scotland and Northern England before migrating to the province of Ulster in Ireland (see Plantation of Ulster) and thence, beginning about five generations later, to North America in large numbers during the eighteenth century.^{[citation needed]}

In the 2000 census, 4.8 million Americans self-reported Scottish ancestry, 1.7% of the total U.S. population. Over 4.3 million self-reported Scotch-Irish ancestry, for a total of 9.2 million Americans self-reporting some kind of Scottish descent. Self-reported numbers are regarded by demographers as massive under-counts, because Scottish ancestry is known to be disproportionately under-reported among the majority of mixed ancestry, and because areas where people reported "American" ancestry were the places where, historically, Scottish and Scotch-Irish Protestants settled in North America (that is: along the North American coast, Appalachia, and the Southeastern United States). Scottish Americans descended from nineteenth-century Scottish emigrants tend to be concentrated in the West, while many in New England are the descendants of emigrants, often Gaelic-speaking, from the Maritime Provinces of Canada, from the 1880s onward. Americans of Scottish descent outnumber the population of Scotland, where 4,459,071 or 88.09% of people identified as ethnic Scottish in the 2001 Census.