Jan Ptaśnik (1876 – 1930) was a Polish historian of medieval and urban history.

His work focused heavily on documenting Italian influence in Poland.

According to historian Wiesław Bieńkowski [pl] writing in the Polish Biographical Dictionary, the initial expectation for Ptaśnik was the priesthood.

[1][2] Ptaśnik then went to Rome to study art, archeology, and diplomatic history.

[2] During his career, Ptaśnik authored multiple books and edited the Monumenta Poloniae Vaticana from 1913.