Jacob Caro (February 2, 1835[1] – December 12, 1904) was a German historian.
After several years of study at the universities of Berlin and Leipzig, he attracted considerable attention by his work Das Interregnum Polens im Jahr 1586, oder die Häuser Zborowski und Zamojski (Gotha, 1861) and was immediately entrusted with the continuation of Röppel's history of Poland in the series of Geschichten der Europäischen Staaten, edited by Arnold Hermann Ludwig Heeren and Friedrich August Ukert, and published at Gotha.
Caro contributed volumes ii through v (1863–88) of this monumental work.
Before publishing the results of his research he undertook several extensive journeys through Galicia and the south of Russia, and upon his return to Germany in 1863 was appointed privat-docent at the University of Jena.
Shortly afterward, at the invitation of Grand Duchess Helena of Russia, he accompanied her on her travels, and was for some time attached to her suite at St. Petersburg.