R. Abraham Hai b. Ezriel Reggio (1755–1846), Italian rabbi and kabbalist. Born in Ferrara, Reggio was a pupil of Isaac Lampronti and his son Solomon. He went to Gorizia where he studied under Moses Hefez (Gentili), the local rabbi, and taught in the talmud torah. After the death of his teacher, Reggio was appointed to succeed him as rabbi of the town (c. 1796), and he held this office until his death. Reggio was considered an important posek in his time. Leading scholars of that period, including Mordecai Baneth, addressed halakhic problems to him.

His only published work is Tiglahat ha-Ma'amar. His most important works, Eshel Avraham, on general principles and themes in the Bible, Mishnah, Talmud, prayer book and Kabbalah; Mazkeret ha-Limmud, novellae; and Mashal u-Melizah, letters, poems, and elegies; remain in manuscript.

הספר נדפס בעילום שם המחבר, בתשובה לספר "מאמר התגלחת" מאת בן המחבר יצחק שמואל רג'יו (יש"ר), בו התיר גילוח בחול המועד. הספר חזר ונדפס בתוך ספרו של מ' בניהו, תגלחת בחולו של מועד, ירושלים תשנ"ה, עמ' שז-שיז. על הספר עיין: שם, עמ' נא-נג.