The marriage may either be void (invalid) from the outset or voidable (subject to attack) because of legal infirmities.
No license or solemnization.
If you did not obtain a marriage license from the Circuit Court Clerk's office or have a marriage ceremony performed by someone who is licensed by the state to perform marriages, then you can have the marriage annulled.
If you or the other party already were married to someone else, the marriage can be annulled. The one who was married also can be prosecuted for the criminal offense of bigamy.
It has been said that the definition of marriage and bigamy are the same:Having one wife too many.
If the marriage is between relatives who are forbidden to marry, by statute, then the marriage can be annulled.
Note: In Virginia, you can marry your first cousin, but not your sister.
Lack of Capacity-Mental Infirmity
If either of the parties lacked the mental capacity to consent to marriage at the time that the marriage was performed( for example, due to extreme intoxication, mental illness), then the marriage can be annulled.
Fraud or Duress
If there was fraud or duress that materially effected the essentials of the marriage, the marriage can be annulled. This would go beyond general "puffing" about one's pedigree or education.
If there is natural and incurable impotence existing at the time of entering into the marriage and the other party did not know of it, the marriage can be annulled.
If either party, without the knowledge of the other, has a felony conviction, the marriage can be annulled.
Pregnancy BY A Third Party
If at the time of the marriage, the wife, without knowledge of the husband, is pregnant with the child of someone else, the marriage can be annulled.
Pregnancy OF A Third Party
If the husband, without knowledge of the wife, fathered a child born to a woman other than the wife within 10 months after the marriage, then the marriage can be annulled.
If either party, without the knowledge of the other, had been a prostitute prior to marriage, then the marriage can be annulled.