I just got married for less than a year and found out my spouse cheated on me during our engagement. Is an Annulment Possible?

You can, but it depends on the state you live in.  Some states allow annulments based on the fact that one spouse never intended to be faithful to the other.  Most states allow for annulments if fraud is an element.  The laws regarding cheating before marriage as it relates to divorce and annulment vary state by state, especially regarding allowable time restraints.  Grounds for an annulment focus on reasons that prove the marriage never should have occurred in the first place, so if your husband was cheating on you before you were even married but were intending to be, you may have the basis for an annulment.  You should consult with a divorce attorney who is familiar with annulments and the issue of cheating before marriage.