He adopted a teaching method based on love rather than punishment, a method known as the Salesian Preventive System.
In Ireland, the Salesians (priests and sisters) have 27 centres for educating and working with young people.
Popularly known as Don Bosco, he is also the patron saint of Catholic stage magicians.
It is the first time the relic has visited Ireland. It is here as part of a worldwide pilgrimage in preparation for the 200th anniversary in 2015 of the saint's birth. The nationwide tour will visit 12 venues.
The glass casket enables those venerating the relic to see the sculptured face of Don Bosco which was made from the saint's death mask.
Inside the replica body, laid out in priestly vestments, tissue from the founder of the Salesian order's right hand and arm is preserved in a large urn.
Full details on the nationwide tour are available at www.donboscorelics.ie