In the Book of Genesis, Noah’s eldest son is Shem.
Genesis names Noah’s three sons as Shem, Ham, and Japheth, with Shem listed first. The biblical account later traces the line of Abraham through Shem, which is why the term “Semitic” was historically connected to his name.
The order of the names is not identical in every passage or tradition, and “eldest” is an interpretive description rather than a universally emphasized title. Shem should also not be confused with Noah’s father, Lamech, or with Shem’s descendants named in Genesis 10.
In the wider flood story, all three sons enter the ark with Noah, their wives, and Noah’s wife. After the flood, Genesis describes Shem as an ancestor in the genealogy leading toward Abraham.