Shemaryahu Gurary, also known by his Hebrew initials as Rashag, (1897–1989) was a rabbi following the Chabad-Lubavitch dynasty of Hasidism.

He was a son-in-law of Yosef Yitzchok Schneersohn, the sixth Chabad-Lubavitch rebbe, and the brother-in-law of Menachem Mendel Schneerson, the seventh.

He worked with his father-in-law in Russia and Poland and moved to the U.S. in 1940.

[1] He was the director in Warsaw of the Tomchei Temimim yeshiva network.

Upon the death of his father-in-law in 1950, he was considered as a possible successor to him but soon ceded his position to his brother-in-law Menachem Mendel Scheerson.