In Vatican City, Pope Francis, who is the leader of the world's 1.2 billion Roman Catholics, is celebrating his first Christmas.
In a packed St. Peter's Basilica, Pope Francis celebrated a Christmas eve mass on Tuesday.
"The Lord is coming. May we await him with open hearts!" Pope Francis earlier tweeted.
People belonging to Christian community prayed at churches while for others it was simply a time for merriment.
With houses and shops decorated beautifully with Christmas trees, ribbons and bells, Christmas fever has surely gripped every corner of the globe on Wednesday.
As a part of Christmas celebration, large number of people have gathered in the biblical town of Bethlehem.
In India, people are celebrating Christmas across the country and Christians are attending special church services to mark the occasion.
In Kolkata, the aroma of home-baked cakes wafted through the narrow lanes of Anglo-Indian ghettos of central Kolkata as the non-Christians joined the party with as much enthusiasm as the Christians.
Mother House, the global headquarters of the Missionaries of Charity (MoC), is celebrating the day with special prayers and mass.
Decorated beautifully with garlands of light, Christmas tress and colourful bells, Park Street, the sunset boulevard of Kolkata, will remain awake for the whole night as more and more people are expected to assemble here to be a part of the festivity.
For the pious, the birth of Jesus is the day to throng the illuminated St. Paul's Cathedral in Kolkata or the Bandel Church on the outskirts of the city for midnight mass.
The day is also one for hitting the outdoors and organizing picnics while long queues were usual scenes at the city's zoo.
Meanwhile, Indian President Pranab Mukherjee, Prime Minister Manmohan Singh and Vice-President M. Hamid Ansari have wished the nation on the occasion of Christmas.
In his message, Pranab Mukherjee said, "On the joyous occasion of Christmas, I extend my heartiest greetings and best wishes to all my fellow countrymen and wish everyone a merry Christmas and prosperous New Year."
"As the world celebrates Christmas this year, may the higher purpose which Jesus Christ held out before mankind prevail. And may the Star that shone over Bethlehem sparkle once again and beckon us onto the path of peace on earth and goodwill amongst men," he said.
Mukherjee said: "Let us recall on this auspicious day the teachings of love and kindness of Jesus Christ who for centuries has been an inspiration to mankind. May the Almighty shower his bounteous blessings on all the people of the world on this festive occasion".
In his message, Prime Minister Manmohan Singh said that Christmas is a celebration of Jesus Christ's teachings of selflessness, tolerance and brotherhood.
"It is an occasion to strengthen the bonds of love and friendship amongst us," Singh said.
"May the spirit of Christmas encourage people to think about those less fortunate he added," he said.
M Hamid Ansari has also extended his greetings and best wishes to all citizens on the occasion of Christmas, commemorating the birth of Lord Jesus Christ, to be celebrated on Wednesday.
In his message, Ansari said: "I extend my greetings and best wishes to all our citizens on the joyous occasion of Christmas, commemorating the birth of Lord Jesus Christ."
"Let us celebrate this happy occasion by dedicating ourselves to Christ's eternal message of love, compassion and forgiveness for all," he said.
"May this joyous festival shower everyone with peace, prosperity and happiness," he said.
Politicians and people from different fields have also greeted the nation on Wednesday.
Gujarat Chief Minister and Bharatiya Janata Party (BJP)'s prime ministerial candidate Narendra Modi tweeted: "Merry Christmas to everyone. May Christmas bring joy, peace, brotherhood & compassion in the world."
Senior BJP leader Sushma Swaraj said:"Merry Christmas to all."
Bollywood superstar Amitabh Bachchan posted on his Twitter homepage: " A merry Xmas and a happy New Year to all .. walking down from street and strains of the choir next door - 'O come let us adore Him'."
Actor Abhishek Bachchan tweeted:"Wish you all a very merry Christmas."
Bollywood superstar Shah Rukh Khan said:" Shooting with an amazingly hard working unit. 25 mins to Christmas, away from families, singing Christmas carols underwater & smiling."
Actor Anupam Kher wished the nation and said: "Merry Christmas. Love, Peace & Happiness Always.:)"
Actress Shabana Azmi tweeted: "Merry Christmas to all. Enjoy the festivities. Time for guilt free indulgence !"
Writer Chetan Bhagat wished his fans and said: "Merry Christmas my extended family!!!"
Tennis star Mahesh Bhupathi greeted his fans and tweeted: "'A King was born today" Merry Christmas folks."
Singer Sunidhi Chauhan posted on her Twitter homepage: "MERRY CHRISTMAS TO ALL!!!! Have a great one :)"
Actor-filmmaker Farhan Akhtar tweeted: "Merry Christmas to all and to all your loved ones."
Actress Arjun Rampal said: "Merry Christmas, everyone."
--IBNS (Posted on 26-12-2013)