Divorce proceedings are referred to as dissolution of marriage actions. In order to file for a dissolution of marriage in California, one of the spouses has to have been a resident of California for six months and a resident of the county where the divorce action is filed for three months immediately before the filing of the divorce petition.
To be considered a resident of California, you have had to actually lived in California for six month with an intent to remain indefinitely. To be considered a resident of the county only requires that you have actually lived in the county for three months.
In order challenge a petition for dissolution of marriage based on a lack of residency, the responding party must typically raise the issue within the 30 day response period by filing a motion to quash the proceeding. Otherwise, the responding party may have waived such an objection.
However, this residency requirement does not apply when a spouse files an action to nullify the marriage or files a petition for legal separation. Hence, one option to get around the residency requirement is to file for legal separation (which does not require the residency requirement), and to amend the petition to seek dissolution of marriage once the residency requirements are met.