How does someone become a saint in the Catholic Church?

In the Catholic Church, a person is officially declared a saint through a formal process called canonization, by which the Pope infallibly defines that a deceased person is in heaven and worthy of universal veneration. The process typically involves investigation of heroic virtue, confirmation of miracles, and the stages of Venerable, Blessed, and finally Saint.

Canonization is the culmination of a careful, multi-stage juridical and theological process overseen by the Dicastery for the Causes of Saints in Rome.