"Pennsylvania Dutch" in Their Own Language: Pennsilfaanisch-Deitsch

The endonym — the name the people use for themselves — is Pennsilfaanisch-Deitsch (pronounced roughly PEN-sil-fahn-ish DYTSH).

Breakdown

• Pennsilfaanisch = Pennsylvania (from English, adapted to Palatine German phonology).
• Deitsch = German / Dutch (cognate with Deutsch); historically meant "German" or "Germanic," not "Dutch" (Netherlands).

Why "Dutch" in English?

Early English speakers used "Dutch" broadly for any Germanic people (cf. "Pennsylvania Dutch" = "Pennsylvania Germans"). The community descends from Palatine, Swiss, Alsatian German-speakers (18th-century immigrants), not Dutch from the Netherlands.

Language Status

• Pennsylvania German (Deitsch) — a West Central German dialect.
• Spoken by ~300,000 Old Order Amish, Old Order Mennonites, and some non-plain descendants.
• Written in both standard German orthography and a phonetic English-based system.

So: Pennsilfaanisch-Deitsch = "Pennsylvania German" — their language, their people, their name for themselves.