Jewish tradition ascribes three canonical texts to Solomon--Proverbs, Song of Songs (also known as Song of Solomon), and Ecclesiastes. This is based on the texts themselves. Proverbs begins "Proverbs of Solomon son of David, king of Israel". Song of Songs begins "The Song of Songs of Solomon", though the text is a dialog. For Ecclesiastes it's a little less obvious, it begins "words of Kohelet, son of David, king in Jerusalem", but Kohelet may be a title.

There are also some books not canonical in the Hebrew bible, but which may be found in certain Christian canons or are in no canon at all ascribed to Solomon. The most notable is the Wisdom of Solomon. Others are the Odes of Solomon and the Wisdom of Solomon--you can read both here.

However, none of these are believed by scholars to actually have been written by Solomon. All are probably pseudoepigraphical (that is, written by someone else and given the name of a famous figure as a literary technique), and written in the first few centuries BCE, several hundred years after Solomon. The historical existence of Solomon is not an agreed-on historical matter to begin with, so actual text demonstrably written by Solomon would be huge.