Yes, he is able to apply for an annulment. Anyone in a presumed valid marriage is eligible to apply for an annulment.
Diocese of Austin:
4. Who can apply for an annulment?
A person who seeks an annulment usually is someone who has been married, is now divorced, and might or might not wish to marry again, specifically in the Catholic Church.
Divorced people, no matter what their religious affiliation, have a carefully-protected right in this Church to ask the Church to determine whether or not their previous marriage was valid. If they are not of the Catholic faith, they seek this generally because they wish to remarry, and the intended spouse is a Catholic who wants the marriage to be recognized by the Catholic Church. We respect the vows of marriage of all people, no matter what their religious affiliation is. Members of the Catholic Church, however, are bound to have their marriage recognized by the Church. This is why members of other churches must often go through an annulment process before they can marry someone in the Catholic Church.