Eberhard Freitag (born 19 May 1942, in Mühlacker) is a German mathematician, specializing in complex analysis and especially modular forms.

Freitag studied from 1961 mathematics, physics and astronomy at Heidelberg University, where he received in 1964 his Diplom and in 1966 his Ph.D. (promotion), supervised by Hans Maaß (and also Albrecht Dold), with thesis Modulformen zweiten Grades zum rationalen und Gaußschen Zahlkörper, published in Sitzungsberichte Heidelberger Akad.

Among other work, Freitag described this theory in two monographs published by Springer Verlag in Grundlehren der mathematischen Wissenschaften.

In 1974 in Vancouver he was an Invited Speaker of the ICM with talk Singularitäten von Modulmannigfaltigkeiten und Körper Automorpher Funktionen.

[2] In 1998 he proved with Rainer Weissauer and Richard Borcherds the existence of a Siegel cusp form of degree 12 and weight 12 using the theta series associated with the 24 Niemeier lattices of dimension 24.