There are hundreds of named men and women in the Old Testament. Merely to list all of their names would fill many pages and be of little profit. If you want to investigate every one of them, I recommend Herbert Lockyer's books, All the Women of the Bible and All the Men of the Bible, or any good Bible dictionary, such as Nelson's New Illustrated Bible Dictionary.
Here are the 100 most significant Old Testament people, based not on what I think or who I like, but on how many chapters are devoted to their lives. You will meet peasants and princes, queens and harlots, shepherds and soldiers.
I have identified each with a short description and a Bible reference. This doesn't mean the reference cited is the only place this person is mentioned. Keep in mind that these are in alphabetical order, not in either chronological order or in the order in which they appear in the Hebrew Scriptures.