Pietrzyk is a Polish surname, like Pietrzak and Pietrzykowski, developed from the given name Piotr, when it was still Pietr, before it stabilized in its present form, Piotr, following the so-called . The Pietrzyk declension is very old, having been recorded as early as the 12th century.
The suffix -ak, like -yk, indicates the paternal origin of the surname; it expressed a diminutive form with a positive emotional connotation; when added to the name Piotr, it likely meant Piotr's son. Archaic feminine forms are Pietrzykowa (by husband), Pietrzykówna (by father); they still can be used colloquially. It may be transliterated as: Petrzyk, Petrzik, Petrzhyk, Petrzhik, Petshik, ÃÂõÃÂÃÂøú.
Notable people with this surname include the following: