Who was the author of Ecclesiastes?

The general consensus of conservative scholars is that King
Solomon wrote Ecclesiastes. The introduction certainly implies this. It
describes the author of the book as “the Teacher, son of David, king in
Jerusalem.” There is only one person who we know was described in his own
time as the Teacher, who was a son of David and who succeeded him as
king. That was Solomon. Another clear reference to Solomon is found in
Ecclesiastes 12:9, which seems to be an epilogue. It describes the author
of the book by saying, “Not only was the Teacher wise, but also he
imparted knowledge to the people. He pondered and searched out and set in
order many proverbs.” Again, we can see Solomon in this description.
Another section in Ecclesiastes also seems to clearly reflect Solomon’s
life. This is Ecclesiastes 2:4-9, in which the author of Ecclesiastes
describes the works he undertook in his lifetime. The details, including
the statement that “I became greater by far than anyone in Jerusalem
before me,” are an obvious reference to Solomon. Besides, the style of
Ecclesiastes is similar in many ways to parts of the Proverbs.

Some scholars would discount the genuine authorship of
Solomon, and such things, ultimately, can not be proved beyond a shadow of
a doubt. Although the authorship cannot be proven beyond a reasonable
doubt, the author definitely implies that he is Solomon. Therefore,
either the book is actually written by Solomon, or it is pseudepigraphic;
which means that it is written by someone who is pretending to be
Solomon. Given the inspired nature of the Bible in general, this seems
to be a very unlikely explanation. It would seem that the most likely
explanation of the book is that, as it clearly claims, it was written by
King Solomon, son of King David of Israel.

John Oakes, PhD