Shemtob Gaguin(e) (5 September 1884 – 30 July 1953) was a British Sephardic rabbi and scion of a famous Moroccan rabbinical dynasty which emigrated to Palestine from Spain at the time of the Inquisition.

Sar Shalom Sharabi, also known as the Rashash, the Shemesh or Ribbi Shalom Mizraḥi deyedi`a Sharabi (1720–1777), was a Yemenite Rabbi, Halachist, Chazzan and Kabbalist. In later life, he became the Rosh Yeshiva of Bet El Yeshiva in the Old City of Jerusalem. His daughter married Rabbi Hayyim Abraham Gagin of Jerusalem, making him the great-great-grandfather of Shem Tob Gaguine, the "Keter Shem Tob." His son was Yitzhak Mizrahi Sharabi and his grandson was Chief Rabbi Chaim Abraham Gagin.