Wis. Stat. § 767.301
No action to affirm marriage or for annulment under s. 767.001(1) (a) or (b) may be brought unless at least one of the parties has been a bona fide resident of the county in which the action is brought for not less than 30 days next preceding the commencement of the action, or unless the marriage has been contracted within this state within one year prior to the commencement of the action. No action for divorce or legal separation under s. 767.001(1) (c) or (d) may be brought unless at least one of the parties has been a bona fide resident of the county in which the action is brought for not less than 30 days next preceding the commencement of the action. No action for divorce under s. 767.001(1) (c) may be brought unless at least one of the parties has been a bona fide resident of this state for not less than 6 months next preceding the commencement of the action.
Wis. Stat. § 767.301
2005 Wis. Act 443 contains explanatory notes.
When a divorce action was brought before the residency requirement was met, an action was never commenced and the petition could not be amended after the requirement was met. Siemering v. Siemering, 95 Wis. 2d 111, 288 N.W.2d 881 (Ct. App. 1980).