The book does not identify its writer. Furthermore the ancient Hebrews could not agree on who wrote it. Consequently many different scholars have made guesses as to who the writer was.
From the patriarchal period Job himself is the favored candidate, though some scholars have nominated Elihu. These men seem to be the most likely of the chief characters to have preserved the record of Job's trials. There are many examples of ancient extra-biblical writings in which the author spoke of himself in the third person, so we need not eliminate Job on that ground. The book reads as though an eyewitness of the events recorded wrote it.
Jewish tradition favored Moses as the writer. Moses recorded other events during the patriarchal period in Genesis, he was familiar with desert life, and he had enough ability to write such a book as this one.
Solomon has supporters mainly because he composed other poetic biblical literature (Proverbs, Ecclesiastes, and Song of Solomon). Moreover there are some similarities between Job and Proverbs such as the relationship between fearing God and being wise.
Other scholars have suggested later writers including Hezekiah, Isaiah, and Ezra.
Of course, the writer may have been none of these individuals. No one knows for sure who wrote Job. I tend to prefer a contemporary of Job or Job himself because of the antiquity of this view and the fact that no one has proved it unsatisfactory.
