Yitzhak Baer (Hebrew: יצחק בער) (born 20 December 1888; died 22 January 1980) was German-Israeli historian and an expert in medieval Spanish Jewish history.
Baer was born in Halberstadt, Germany, in 1888. He studied philosophy, history and classical philology at Berlin University, University of Strasbourg and University of Freiburg.
He emigrated to Mandate Palestine, now Israel, in 1930, and began lecturing in medieval Jewish history at the Hebrew University of Jerusalem. He was professor of medieval history at the University from 1932 to 1945.
- Studien zur Geschichte der Juden im Konigreich Aragonien: wahrend des 13. und 14. Jahrhunderts/ von Fritz Baer. Berlin: E. Ebering, 1913
- Das Protokollbuch der Landjudenschaft des Herzogtums Kleve: erster Teil: die Geschichte des Landjudenschaft Herzogtums Kleve/ von Fritz Baer. Berlin: C.A. Schwetschke, 1922
- Untersuchungen über Quellen und Komposition des Schebet Jehuda/ von Fritz Baer. Berlin: C.A. Schwetschke, 1923
- Galut'/ Jizchak Fritz Baer. Berlin: Shocken, 1936
- Land of Israel and Exile to the Medieval Ages. Jerusalem, 1936.
- History of Jews in Christian Spain. Tel Aviv: Am Oved 1945, revised and expanded 1959.
- Peoples of Israel: Studies in the History of the Second Temple Period of the Mishna, the Foundations of Law and Faith. Jerusalem: Bialik Institute, 1955.
- Exile (translated from German): Israel Eldad, Bialik Institute, Jerusalem, 1980.
- Studies and Essays in the History of Israel (in Hebrew), 1985. Jerusalem: Israeli Historical Society, 1985.