In the Noah's Ark account, Shem is the son listed first after the flood. Genesis 9:18 names Noah's sons as Shem, Ham, and Japheth in that order.
Shem receives special attention in the biblical genealogies. Genesis 10 presents the descendants of all three sons, while Genesis 11 follows Shem's line to Abram, later called Abraham. This genealogy connects the post-flood family narrative with the patriarchal stories.
The order of names is not always a simple statement about birth order. Genesis 10:21 contains wording that has been interpreted in different ways concerning Shem's relationship to Japheth, and translations vary in how they phrase it. The safe textual fact is that Shem is listed first in Genesis 9:18 and in the genealogy that follows.
Ham and Japheth remain central to the account as well. The three sons are presented together as the ancestors of peoples after the flood, but later interpretations of their descendants differ.