The Pennsylvania Dutch (perhaps more strictly Pennsylvania Deitsch, Pennsylvania Germans or Pennsylvania Deutsch) 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 the word "Dutch" 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. 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 term "Deitsch". It is worth noting that the adjective "German" is "Deutsch" in the German language and "Duits" in the Dutch language. Also some southern German dialects still pronounce "Deutsch" as "Deitsch" (Daɪt). The difficulty is enlarged by the fact that the oldest native term for the Dutch language happens to be Dietsch, a stem that also shows up in the derivation of Plautdietsch. Plautdietsch developed on a mixed Dutch / Low German substrate, according to the Dutch linguist Ad Welschen (2000), which is certainly not the case with Pennsylvania Deitsch. So Deitsch etymologically means 'German', while Dietsch means 'Dutch' .

Pennsylvania Dutch 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 and Switzerland 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.