Question
Was Ezra a Kohen Gadol?
Answer
The Rambam says (in the introduction to the Mishneh Torah) that Shimon ha-Tzadik “was the kohen gadol after Ezra”, but that doesn’t imply that Ezra himself was a kohen gadol. The Mishnah (Parah 3:5) lists the people who made parah adumahs; most of them were kohanim gedolim, and one of them was Ezra, but the first one was Eleazar, who wasn’t a kohen gadol.