A special service is taking place which will see Benedict XVI officially become the new Pope.
The Mass is being held in St Peter's Square in Rome and there are loads of world leaders and royalty there.
The Pope will be given a special ring and a piece of white wool with crosses on called a pallium, which are both traditional symbols of religious power.
At least 500,000 people gathered to watch the ceremony, and there are loads of security measures in place.
The Pope, 78, started the ceremony by walking up to St Peter's Basilica with the Roman Catholic cardinals.
He was dressed in gold and white robes.
Some of the special guests at the service include Prince Philip, the Archbishop of Canterbury, King Juan Carlos of Spain and Germany Chancellor Gerhard Schroeder.