25 December 2013
Last updated at 09:14 ET
Pope Francis asked the faithful gathered in St Peter's Square to pray for a peaceful end to violence in Syria and other conflict zones during his first Urbi et Orbi message.
Hundreds of Syrian and Iraqi refugees, along with Jordanian Christians, prayed for peace in St Afram's Syrian Orthodox church in the Jordanian capital, Amman.
In Pakistan, Christians celebrate Mass at All Saints in Peshawar. Two suicide bombers blew themselves up outside the church in September, killing almost 100 people.
In Bangui, the capital of the Central African Republic, Catholic priests celebrated a special Mass for children displaced by violence.
In Istanbul, Patriarch Bartholomew I led a Nativity Liturgy at the Greek Orthodox patriarchal Cathedral of St George.
As is tradition, the Queen and members of the Royal Family attended a Christmas service in Sandringham, in Norfolk.
Crowds lined the path taken by Prince William and the Duchess of Cambridge on their way to attend the church service in Sandringham. Many had hoped to catch a glimpse of five-month-old Prince George.
At the Church of the Nativity in Bethlehem, worshippers queued to visit the gold star which marks the sport where Jesus is believed to have been born.
In Barcelona, swimmers jumped into the cold waters of the port to compete in the Christmas Cup, which has been held for more than a century.
Lifeguards pose in front of their Christmas tree on Bondi Beach in Sydney, Australia.
On the Potomac river in the US state of Maryland, a water-skier dressed as Santa Claus was joined by another in a reindeer outfit on Christmas Eve.