In the Genesis Flood story, Shem is presented as an ancestor of the Israelites.
Genesis 10 and 11 trace a genealogical line from Shem through several generations to Terah and then to Abraham. Abraham is the patriarch whose descendants become the Israelites in the biblical narrative. For that reason, Shem is traditionally regarded as an ancestor of the Israelites through this line.
Shem was one of Noah’s three sons, alongside Ham and Japheth. The genealogies assign different peoples and regions to the descendants of the three brothers, although these lists are theological and traditional frameworks rather than modern population genetics.
The term “Semite” was later formed from Shem’s name, but modern scholars use “Semitic” primarily as a linguistic classification for a language family. It should not be treated as a precise biblical ethnic label. The direct genealogical answer in Genesis is nevertheless Shem.