Kayyara, Simeon, 9th cent.

Simeon Kayyara, also spelled Shimon Kiara (Hebrew: שמעון קיירא), was a Jewish-Babylonian halakhist of the first half of the 8th century. Although he lived during the Geonic period, he was never officially appointed as a Gaon, and therefore does not bear the title "Gaon". Rabbinic sources often refer to Kayyara as Bahag, an abbreviation of Ba'al Halakhot Gedolot ("author of the Halakhot Gedolot"), after his most important work.