Binyamin HaTzaddik was a Tanna whose period is unknown. The Babylonian Talmud mentions him only once, in tractate Bava Batra (11a), where he is described as the overseer of his community's charity fund.

The Talmud relates that in a year of drought a woman came and asked him to support her. He answered that there was nothing left in the charity fund. She replied that if he did not support her, a woman and her seven children would die, and he supported her from his own money. Later he fell gravely ill and was close to death. The ministering angels pleaded before the Holy One, blessed be He: whoever sustains a single soul of Israel is as if he sustained an entire world, so should Binyamin HaTzaddik, who kept a woman and her seven children alive, die after so few years? His decree was immediately torn up, and twenty-two years were added to his life.

The scholar Mordechai Margaliot proposed identifying him with the Tanna Abba Binyamin, who is quoted four times in the Babylonian Talmud in aggadic passages. Other identifications have also been suggested, and he may be a different sage altogether.

Rabbi Chaim Vital mentions his grave in Safed in Shaar HaGilgulim, in the name of the Arizal. Today it is marked on Lochamei HaGetaot Street in Safed's Darom neighborhood, in a small synagogue that is not part of any cemetery. According to tradition, his hilloula is held on 29 Av, the eve of Rosh Chodesh Elul.