German rabbi; born probably in Glogau; died at Ansbach, Bavaria, 1780; was a descendant of the Ẓebi family (see Brüll's "Jahrb." 1:87-122). In 1763 he was elected rabbi of Berlin, having previously been rabbi of Dessau. Mendelssohn put his name on the title-page of a thanksgiving sermon which Mosessohn had written after the peace of Hubertsburg in 1763. The sermon appeared under the title "Aaron Mosessohn's Friedenspredigt ins Deutscheübersetzt von R. S. K." Berlin, 1763. It was reprinted in Mendelssohn's "Gesammelte Schriften," 6:407-415, and translated into Hebrew in "Ha-Me'assef," 1789, pp. 14-24.
Aaron edited "He-'Aruk mi-ShaK" (Berlin, 1767), the commentary of his great-grandfather Shabbethai Cohen on the Shulḥan 'Aruk, Yoreh De'ah, to which he added notes of his own. About 1771 he accepted the rabbinate of Schwabach, with which the office of chief rabbi of the principality of Ansbach was united. Upon his recommendation the congregation of Berlin conferred upon Mendelssohn honorary membership, April 3, 1771.