R. Malachi ben Jacob ha-Kohen (d. 1785–1790) was an Italian scholar. Little is known of his life. He was the pupil of R. Abraham Hayyim Raphael Rodrigues and of the kabbalist R. Joseph Ergas, whom he succeeded as rabbi of Leghorn after the latter’s death in 1730. R. Malachi arranged R. Ergas' work Divrei Yosef for publication (Leghorn, 1742). He also drew up an order of service Shivhei Todah ("Praises of Thanksgiving"; Leghorn, 1744), for the 22nd day of Shevat, an annual fast day proclaimed to commemorate the rescue of the Leghorn community from the earthquake of 1742. He lived to an old age, dying in Tripoli, where he had apparently served as an emissary for Erez Israel. His novellae and responsa are found in the works of contemporary scholars. A manuscript of his responsa, Teshuvot Yad Malakhi, was published by E. Gruenhut in Ha-Me’assef, 5 (1900). R. Malachi was also a liturgical poet. He composed Sefer Shirei Zimrah, which includes poems and dirges, part of which was published by S. Bernstein (Mizrah u-Ma'arav, 3 (1929), 245–61). His poem written on the occasion of the inauguration of the synagogue in Leghorn in 1742 was also published in Piperno's Kol Ugav (Leghorn, 1846).

עם ההסכמות מן ההוצאה הראשונה. דף ו,א: הג"ה, מאת... מו"ה צבי (הירש [לוין]) ז"ל... אב"ד... בערלין... מצאתי מכ"י [מכתב-ידו]... בק"ק לונדון. [1] דף: קצת הגהות... מו"ה יצחק דוב הלוי [באמבערגער] ני' אב"ד דק"ק ווי"ב (ווירצבורג). בסופן הערה מאת המו"ל, אפרים הערץ.