His father died when he was two years old. As soon as he was old enough to do odd jobs, John did so to support his family. John would go to circuses, fairs, and carnivals. Picking up the tricks he saw magicians perform; he put on shows. At the end of each performance, he would repeat the homily he had heard earlier that day in church.

He worked as a tailor, baker, shoemaker, and carpenter while attending college and seminary, being ordained in 1841. Working as a teacher, he constantly worked with young people, finding places where they could meet, play, pray, and taught catechism to orphans. John founded the Salesians of Don Bosco in 1859 for priests to work with and educate boys, under the protection of Our Lady, Help of Christians, and Saint Francis de Sales.