The Pennsylvania Dutch (Pennsylvania German: Pennsylvanisch Deitsche), also referred to as Pennsylvania Germans, are an ethnic group in Pennsylvania in the United States, Ontario in Canada, and other regions of both nations. They largely originate from the Palatinate region of Germany, and settled in Pennsylvania during the 17th, 18th, and 19th centuries. While most were from the Palatinate region of Germany, a lesser number were from other German-speaking areas of Germany and Europe, including Baden-Württemberg, Hesse, Saxony, and Rhineland in Germany, Switzerland, and the Alsace–Lorraine region of France.

The Pennsylvania Dutch are either monolingual English speakers or bilingual speakers of both English and the Pennsylvania Dutch language, which is also commonly referred to as Pennsylvania German. Linguistically it consists of a mix of German dialects which have been significantly influenced by English, primarily in terms of vocabulary. Based on dialect features, Pennsylvania Dutch can be classified as a variety of Rhine Franconian, with the Palatine German dialects being most closely related.

Geographically, Pennsylvania Dutch are largely found in the Pennsylvania Dutch Country and Ohio Amish Country. The main division among Pennsylvania Dutch is that between sectarians (those belonging to the Old Order Mennonite, Amish or related groups) and nonsectarians, sometimes colloquially referred to as ″Church Dutch″ or ″Fancy Dutch″.

Notable Americans of Pennsylvania Dutch descent include Henry J. Heinz (founder of the Heinz food conglomerate), Walter Chrysler (founder of Chrysler the automobile manufacturer), U.S. President Dwight D. Eisenhower, and Meghan, Duchess of Sussex.

Differing explanations exist on why the Pennsylvania Dutch are referred to as Dutch, which typically refers to the inhabitants of the Netherlands or the Dutch language. The Dutch language and German language form a dialect continuum. There is no sudden change in how people speak from one location to another between the Netherlands and Germany. Dialects of Luxembourg, France, and Germany that are near Belgium and the Netherlands exist in the gray area of this continuum, and are closely related to Dutch and German.

Some authors consider the word Dutch in Pennsylvania Dutch, which in medieval times could also be used to refer to speakers of various German dialects, to be an archaism specific to 19th-century American English, particularly in its colloquial form. Other scholars contend that the Dutch in Pennsylvania Dutch is an anglicization of the Pennsylvania German autonym deitsch, which in the Pennsylvania German language refers to the Pennsylvania Dutch or Germans in general.

The migration of the Pennsylvania Dutch to the United States predates the emergence of a distinct German national identity, which did not form until the late 18th century. The formation of the German Empire in 1871 resulted in a semantic shift, in which deutsch was no longer principally a linguistic and cultural term, but was increasingly used to describe all things related to Germany and its inhabitants. This development did not go unnoticed among the Pennsylvania Dutch who, in the 19th and early 20th century, referred to themselves as Deitsche, while calling newer German immigrants Deitschlenner lit. 'Germany-ers'.

The Pennsylvania Dutch live primarily in the Delaware Valley and in the Pennsylvania Dutch Country, a large area that includes South Central Pennsylvania, in the area stretching in an arc from Bethlehem and Allentown in the Lehigh Valley westward through Reading, Lebanon, and Lancaster to York and Chambersburg. Smaller enclaves include Pennsylvania Dutch-speaking areas in New York, Delaware, Maryland, Ohio, West Virginia, North Carolina, Indiana, Illinois, Wisconsin, Virginia, and the Canadian province of Ontario.