P.Syd.

Paul Sydow (1 November 1851 in Kallies – 26 February 1925 in Sophienstädt near Ruhlsdorf) was a German mycologist and lichenologist, father of Hans Sydow (1879–1946).

He worked as a schoolmaster in Berlin. With his son, Hans, he authored works involving descriptions of new species of ascomycetes, rusts and smuts.

He also made contributions to Volume 16 of Pier Andrea Saccardo's Sylloge fungorum omnium hucusque cognitorum.