Shem was a Nephite land and city to which Mormon withdrew his people around A.D. 345, after they were driven northward from the land of Jashon by the Lamanites (Mormon 2:20). It lay north of the lands of Antum and Jashon, where Ammaron had deposited the Nephite records and from which Mormon took the plates of Nephi (Mormon 1:3; 2:16–17).
At Shem, Mormon fortified the city and gathered as many of his people as he could in hope of saving them from destruction (Mormon 2:21). When the Lamanites attacked again in the year 346, Mormon urged his people to stand and fight for their wives, children, and homes; an army of thirty thousand Nephites met fifty thousand Lamanites and drove them off, then pursued and beat them, though Mormon records that the strength of the Lord was not with them (Mormon 2:22–26).
The record gives no further detail about the city and land of Shem beyond its location north of Jashon and Antum. Earlier in his account Mormon describes the land in his youth as covered with buildings and a people almost as numerous as the sand of the sea (Mormon 1:7).