"No fault" divorce describes any divorce where the spouse asking for a divorce does not have to prove that the other spouse did something wrong. All states allow no fault divorces.
To get a no fault divorce, one spouse must simply state a reason for the divorce that is recognized by the state. In most states, it's enough to declare that the couple cannot get along (this reason goes by such names as "incompatibility," "irreconcilable differences," or "irremediable breakdown of the marriage").
In some states, however, the couple must live apart for a period of months or years before they can obtain a no fault divorce.
How does your state handle no fault divorce? Check out Nolo's article collection Divorce in Your State to find out.