Isaac ben Meir (c. 1090 – c. 1130), also known as the Rivam after his Hebrew acronym, was a French rabbi and one of the Baalei Tosafos. He was the grandson of Rashi, and brother of the Rashbam and the Rabbeinu Tam. His father was Meir ben Samuel and his mother was Yocheved, the daughter of Rashi. He died before his father, leaving four children. Although he died young, the Rivam contributed to Tosafos, mentioned by Eliezer ben Joel HaLevi (Abi ha-'Ezri, §417), to several tractates of the Talmud. Isaac himself is often quoted in the edited Tosafos (Shab. 138a; Ket. 29b et passim).
- Jacob Tam, Sefer ha-Yashar, No. 616, p. 72b, Vienna, 1811.