In the Philippines, there has been a massive outpouring of emotion. Most of its population is Catholic - more than 85 million people - the biggest Catholic population in Asia, and third in the world after Brazil and Mexico.
The president of the Philippine Catholic Church, Cardinal Virgilio David, has asked all the parishes to ring their bells and to pray for Pope Francis. Easter Monday masses have been turned into mourning services.
One artist's image that's quickly gone viral on Philippine social media shows the Pope's zucchetto - his skullcap - hovering above his head and transforming into a halo.
Many are sharing their memories of the Pope's visit in 2015, particularly to the typhoon-hit area of Tacloban, which was interrupted by storms.
"In sunshine or under the rain, he made us feel the love of God. The rains and our tears of joy were mixed, running down our cheeks," said Socrates B Villegas, the Archbishop of Lingayen and Dagupan.