Mother Teresa was officially declared a Catholic saint on 4 September.
Pope Francis led a packed canonisation ceremony at Vatican City, where the nun from Yugoslavia was proclaimed a saint a whole 19 years after her death.
"For the honour of the Blessed Trinity, we declare and define Blessed Teresa of Kolkata to be a Saint and we enroll her among the Saints," Pope Francis said.
In order to celebrate the canonisation, Pope Francis invited around 1,500 homeless people for a pizza lunch.
Watch a portion of Pope Francis' speech here:
A 12-member central delegation led by External Affairs Minister Sushma Swaraj and two state government-level delegations from Delhi and West Bengal, led by Chief Ministers Arvind Kejriwal and Mamata Banerjee are in Rome to attend the ceremony. A group of around 40-50 nuns from different parts of the country, led by Missionaries of Charity Superior General Sister Mary Prema, also attended the function.
People were also seen waving the Indian national flag at the ceremony. Many took to social media to express their joy at the sight.
Vatican: Pope Francis proclaims Mother Teresa as Saint pic.twitter.com/VI17MV7qzc— ANI (@ANI_news) September 4, 2016
In India, crowds thronged Mother Teresa's tomb to pay homage to the saint.