For those entering the priesthood, does the Vatican pay for their tuition?
For religious, their religious institute covers the costs.
For dioceses, it is up to the diocese how to cover the costs.
Some dioceses pay for the major seminary and require you to do student loans for any undergraduate work that is necessary to met the requirements of the major seminary. Some dioceses pay for the major seminary but then require the man to pay back the diocese a portion of the costs (one I was looking into it was half) after they are ordained.
I imagine that this would only be the case if you are studying for the diocese of Rome.
The diocese pays for diocesan priests. In my diocese (Salford, England) we have an annual collection at the end of Mass for the Ecclesiastical Education Fund, which finances the training of diocesan priests.
The Knights of Columbus also sponsor seminarians and pay for part of their tuition and personal needs.
The Vatican is not in the Diocese of Rome. The Vatican is a separate country. It does not belong to the Italian Catholic Conference of Bishops nor is it a diocese. The pope is the bishop of Rome, but that’s a separate office. The Diocese of Rome finances itself, just like any other diocese in Italy.
There are funds at the Vatican for dioceses in developing nations. They have to write proposals for these, just as you would write a proposal for a grant from any organization.
It is up to the faithful in the diocese to fund the education of their priests. In some dioceses the cost is shared between the faithful and the seminarian. As Br. David pointed out, some seminarians pay for part of their education.
Even in religious orders, until you’re a novice, the order may pay for your education, but it has no canonical obligation to do so. When I entered, I had to pay for my first two years of college. Then I went to novitiate. From that point forward, the order paid for my education. Even there, the cost was shared. Many of our friars hold positions that pay salaries: parishes, schools, hospitals, counseling, etc. Every house sends a percentage of its income to the motherhouse. The rest of the money comes from begging. The faithful help us.
Br. JR, OSF