Shem is named first among Noah’s sons in the genealogy that follows the Ark story.
Genesis 9:18 lists Shem, Ham, and Japheth as Noah’s sons after the flood narrative. Genesis 10 then develops a table of nations associated with Noah’s sons and their descendants. Shem is presented first in the biblical listing, although the text also provides separate information about the other two brothers.
Shem is especially important in the genealogical tradition because Genesis 11 traces a line from Shem through several generations to Abram, later called Abraham. The term “Semitic” was historically derived from Shem’s name, although modern linguistic classification is more precise than simply equating a language family with a biblical ancestor.
The question asks for the first son named in the listing, not the oldest son by a separately established modern age calculation. Ham and Japheth are also Noah’s sons, so the wording matters: the canonical answer is the first name given in Genesis 9:18.