The PM has recorded a message of welcome to the Pope on a video posted on the No. 10 website.
David Cameron says the visit will be "a very special four days, not just for our six million Catholics, but for many people of faith right across Britain and millions more watching around the world".
He adds: "It's a unique opportunity to celebrate the enormous contribution that all our faith communities make to our society and to celebrate their role in helping to build a bigger and stronger society."
The prime minister also said society should be about "more than materialism" and should instead be about shared values and working for the common good.
He went on to say: "Of course, not everyone will agree with everything the Pope says, but that should not prevent us from acknowledging that the Pope's broader message can help challenge us to ask searching questions about our society and how we treat ourselves and each other.
"The Holy See can also be a partner for us with great influence across the world and we have incredibly important work to do together on fighting poverty and disease, on winning the argument to get to grip with climate change, and on promoting a multi-faith dialogue and working for peace across our world."