Shmuel Yitzchok Bornsztain (born 1961), also spelled Borenstein or Bernstein, is the sixth Rebbe of the Sochatchov Hasidic dynasty.

In the early 1980's, Bornsztain married Rivka Shternbuch a granddaughter of Grand Rabbi Boruch Hager of Seret-Vihznitz.

Rivka's father, Rabbi Eliyahu Shternbuch was the Av Beit Din of the Machzikei Hadaas Kehilla.

Bornsztain's son, Meir, is married to a daughter of Grand Rabbi Nachum Dov Brayer of Boyan.

In 1987, 18 years after the sudden death of his father, Bornsztain acceded to the position of Sochatchover Rebbe.