But no special celebrations were planned for the leader of the world's 1.2 billion Catholics, with Tuesday expected to be a normal working day for him.
The pope celebrated his daily mass in the Santa Marta chapel at 7 am (0600 GMT), and was preparing his speech for his weekly audience, scheduled for Wednesday.
Francis was given a surprise party at the weekend, when he met a group of children at a charity office inside the Vatican.
They each sported a letter of the alphabet on their shirt, and lined up to spell out the message Happy Birthday, Pope Francis. There was also a cake, with candles.//DPA