"Will he have to become Catholic?”
No. The Catholic Church recognizes the natural right of adult persons to validly enter marriage. This recognition is not limited to Catholics or even to Christians.
The marriage of a Catholic to a person who is not baptized is known as a “disparity of cult,” a severe-sounding phrase with the good intention of reminding us that strongly held religious differences need to be discussed and given sufficient attention prior to marriage. These marriages require dispensation from the bishop. The ceremony can be short and can even serve as a vehicle for increased Jewish-Catholic understanding. An invitation could be offered for a Jewish family member to proclaim the first reading since it traditionally comes from the Hebrew scriptures. A rabbi can offer a blessing.
The Catechism of the Catholic Church states that religious differences don’t constitute “an insurmountable obstacle for marriage” if the engaged parties are respectful and open about the gifts and differences they have received from their respective religious communities. Essentially, the church challenges both partners to be conscious of their religious commitments and to express them to one another with integrity. The Catholic party is challenged to do all that is possible to baptize and raise children as Catholics.
Read full article on US Catholic website