Can a divorce be overturned after it is final?

What do you mean by "overturned"? If you mean revisit or change some of the terms (including support obligations or custody), then you can either appeal the judgment of divorce and its terms (if you feel the terms are in error, and are not supported by the facts and law) or make a motion to modify them, such as due to some change in circumstances.

If you mean undo the divorce and remain married--no. Technically, if there was some substantial procedural defect (e.g. the court the action was brought in did not actually have jurisdiction; improper service; etc.), it *might* be possible to have the case dismissed on appeal, but that would only be a temporary win at best--if your spouse wants to be divorced, he/she will re-file a new case and get the divorce. Everyone has the right to be divorced: you cannot keep someone married against their will in the U.S. So the best you could do would be to force them--and you--to spend more money on the appeal then on a second divorce case, and even that much is unlikely: it would take a very glaring procedural problem to get them that much.