Pope Francis will preside over a solemn canonisation mass in the presence of 100,000 pilgrims and with a giant haloed portrait of Teresa smiling down from St Peter's Basilica.
The sainthood ceremony, for which the Vatican could easily have issued twice as many tickets, comes one day short of the 19th anniversary of Teresa's death, at 87, in the Indian city where she spent her adult life, first teaching, then tending to the dying poor.
Born to Kosovar Albanian parents in Skopje - then part of the Ottoman empire, now the capital of Macedonia - she won the 1979 Nobel peace prize and was revered around the world as a beacon for the Christian values of self-sacrifice and charity.
She was simultaneously regarded with scorn by secular critics who accused her of being more concerned with evangelism than with improving the lot of the poor.
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A picture of her as someone who was just as comfortable flying around in a private plane as clutching the hand of a dying patient has also emerged to counterbalance her saintly image.
Sceptics will be absent from the Vatican today however as Francis pays homage to a woman he sees as the embodiment of his vision of a "poor church for the poor".
"This witness to mercy in our time will join the vast array of men and women who, by their holiness of life, have made the love of Christ visible."
By historical standards, Teresa has been fast-tracked to sainthood, thanks largely to one of the few people to have achieved canonisation faster, John Paul II.
The Polish cleric was a personal friend of Teresa and as the pope at the time of her death, he was responsible for her being beatified in 2003.