Pennsylvania Dutch (Deitsch, or Pennsilfaanisch), sometimes referred to as Pennsylvania German, is a variety of Palatine German, also known as Palatinate German or Palatine Dutch, spoken by the Pennsylvania Dutch, including the Old Order Amish, Old Order Mennonites, Fancy Dutch, and other descendants of German immigrants in the United States and Canada. There are approximately over 300,000 native speakers of Pennsylvania Dutch in the United States and Canada.
The language traditionally has been spoken by the Pennsylvania Dutch, who are descendants of late 17th- and early to late 18th-century immigrants to Pennsylvania, Maryland, Virginia, West Virginia, and North Carolina who arrived primarily from Southern Germany and, to a lesser degree, from eastern French regions of Alsace and Lorraine, and parts of Switzerland. Although the term Pennsylvania Dutch is often taken to refer to the Amish and related Old Order groups, it does not imply a connection to any particular religious group.
The word Dutch does not refer to the Dutch language or people; it is derived from the endonym Deitsch. The terms Deitsch, Dutch, Diets, and Deutsch are all descendants of the Proto-Germanic word *þiudiskaz, which translates in English as "popular" or "of the people". The continued use of the term was strengthened by the Pennsylvania Dutch in the 19th century as a means to distinguish themselves from German immigrants who arrived in the United States after 1830. The Pennsylvania Dutch refer to themselves as Deitsche and to the later German settlers as Deitschlenner (literally "Germany-ers'") who they saw as a related but distinct group of Germans.
Speakers of the dialect today are primarily found in Pennsylvania, Ohio, Indiana, and other Midwestern states of the United States, and in Ontario in Canada. The dialect historically was also spoken in other regions where its use has largely or entirely faded. The practice of Pennsylvania Dutch as a street language in urban areas of Pennsylvania, including Allentown, Reading, Lancaster, and York, was declining by the beginning of the 20th century.