The Pennsylvania Dutch (more strictly, Pennsylvania Germans) are the descendants of German immigrants who came to Pennsylvania prior to 1800. According to Don Yoder, a Pennsylvania German expert and retired University of Pennsylvania professor, the word "Dutch" in this case owes its origin to an archaic meaning where it designated groups that are today considered German and Dutch — prior to the Thirty Years' War, the Netherlands were part of the Holy Roman Empire and the Dutch were generally regarded as one of several German peoples. This is also reflected in the fact that the German endonym (Deutsch), the archaic Dutch endonym (diets(ch)) and the modern Dutch word for "German" (duits) are all cognates. Although Yoder rejects other explanations, other sources, such as Hostetler (1993) give the origin of "Dutch" as a corruption or a "folk-rendering" of the Pennsylvania Dutch's endonym "Deitsch".

Pennsylvania Dutch are or were historically speakers of the Pennsylvania German language. They are a people of various religious affiliations, most of them Lutheran or Reformed, but many Anabaptists as well. They live primarily in southeastern Pennsylvania in the area stretching in an arc from Bethlehem and Allentown through Reading, Lebanon, and Lancaster to York and Chambersburg. They can also be found down throughout the Shenandoah Valley (the modern Interstate 81 corridor) in the adjacent states of Maryland, Virginia, West Virginia and North Carolina, and in the large Amish and Mennonite communities in Mifflin County, Pennsylvania, in Ohio north and south of Youngstown and in Indiana around Elkhart. Their cultural traditions date back to the German immigrations to America in the 17th and 18th centuries. Only then did German immigration from various parts the southern Rhineland, Palatinate, the southern part of Hesse, Baden, Alsace Switzerland, and Tyrol Austria gain momentum, and soon dominate the area. But the Pennsylvania Dutch language is ultimately a derivative of Palatinate German.

Pennsylvania Dutch from the Palatinate of the Rhine

Many Pennsylvania Dutch are descendants of refugees from the Palatinate of the German Rhine. For example, most Amish and Mennonite came to the Palatinate and surrounding areas from the German speaking part of Switzerland, where, as Anabaptists, they were persecuted, and so their stay in the Palatinate was of limited duration.

The first major emigration of Germans to America resulted in the founding of the Borough of Germantown in northwest Philadelphia County, Pennsylvania in 1683-1685. Mass emigration of Palatines began out of Germany in the early 1700s. In the spring of 1709, Queen Anne had granted refuge to about 7,000 Palatines who had sailed the Rhine to Rotterdam. From here about 3,000 were sent to America either directly, or through England, bound for William Penn's colony. The remaining refugees were sent to Ireland to strengthen the Protestant presence in the country. By 1710, large groups of Palatines had sailed from London, the last group of which was bound for New York. There were 3,200 Palatines on 12 ships that sailed for New York and approximately 470 died en route to America. In New York, under the new Governor, Robert Hunter, Palatines worked for British authorities and produced tar and pitch for the Royal Navy in return for their safe passage. They also served as a buffer between the French and Natives on the frontier and the English colonies. In 1723, some 33 Palatine families, dissatisfied under Governor Hunter's rule, migrated from Schoharie, NY, to Tulpehocken, Berks County, PA, where other Palatines had settled.