New Zealand was one of the first nations to celebrate the start of 2015.
A huge fireworks display from the top of Auckland's Sky Tower could be seen across the country's biggest city.
Australia was the next country to ring in the new year, with crowds gathering around Sydney Harbour for the annual firework display.
Fireworks lit up the sky above iconic landmarks like the Sydney Opera House and Harbour Bridge.
The display used more than 10,000 aerial fireworks, 25,000 shooting comets, and 100,000 pyrotechnic effects.
Local media estimated that 1.6 million people crowded along the Harbour foreshore to watch the display.
In Japan's capital, people released balloons outside the Tokyo Tower to ring in 2015.
The balloons carried wishes for the new year.
At Tokyo's Kanda shrine, a Shinto priest welcomed worshippers looking to pray for the wellbeing of their loved ones.
Naked men in loincloths at the shrine pounded steamed rice into a mochi, a rice cake made to celebrate the new year.
In South Korea, people gathered at Imjingak peace park near the Demilitarized Zone dividing the country from North Korea.
A huge traditional bell was rung to welcome the new year.
In the capital Seoul, buddhists lit candles at the Bongeun temple.
Fireworks also erupted over the temple in celebration.
Couples posed for their first selfies of 2015.
In Hong Kong, a majestic display of pyrotechnics lit up Victoria Harbor.
The city's observation wheel proved a fantastic vantage point.
In Malaysia, colorful explosions lit up the sky near the Petronas Twin Towers in Kuala Lumpur.
While in Singapore, fireworks erupted from a floating installation in Marina Bay.
The installation was made up of 25,000 "wishing spheres" on which people had penned their hopes for 2015, which marks the 50th year of the city-state's independence.
In the Philippines, Manila was the scene of a large fireworks display.
Filipinos also watched a laser show on buildings in downtown Manila.
At the Vatican, Pope Francis arrived for the New Year's Eve vespers Mass in St. Peter's Basilica.
The traditional Dec. 31 Mass contains the thanksgiving hymn "Te Deum" to end the year.
In North Korea, a fireworks display ushered in 2015 in Pyongyang's Kim Il Sung Square, named after the country's former leader.
Schoolchildren also performed in a concert in the capital's Central Youth Hall.
The performance was entitled "We Are The Happiest in the World."
In the Chinese city of Harbin, people released sky lanterns to herald the new year.
Elsewhere in China, the National Stadium in Beijing was lit up with the words "Year 2015."
People went ice-skating outside the stadium, known as the Bird's Nest, to mark Beijing's bid to host the 2022 Winter Olympics.
Meanwhile in Shanghai, lights and lasers illuminated buildings as part of a countdown celebration.
In India, school teachers arranged a floral display in the western city of Ahmedabad in the final hours of 2014.
Students then spelled out a welcoming message.
In Russia, fireworks illuminated the frigid sky over St. Basil's Cathedral and Kremlin's Spasskaya Tower in Moscow.
The city of Baku in Azerbaijan served as the stage for the nation's fireworks show.
And in Edinburgh, Scotland, thousands of revelers gathered along Princes Street to sing and dance.
Fireworks also exploded over the ancient Parthenon temple at the Acropolis in Athens.
In Indonesia, fireworks brightened the sky above the Hill Gundaling in North Sumatra.
Fireworks exploded in dramatic fashion behind the quadriga of the landmark Brandenburg Gate in Berlin, Germany.
Thousands of people, meanwhile, packed Sol Square to celebrate the new year in Madrid, Spain.
While in Beirut, Lebanon, people set off balloons to mark the start of 2015.
In England, fireworks engulfed the iconic London Eye.
And in France, the Arc de Triomphe served as the fireworks backdrop for hundreds of revelers.
In Skopje, Macedonia, fireworks exploded over the Archaeological Museum
Hundreds also gathered at Castle Square in Warsaw, Poland, to celebrate the new year.
In Sarajevo, some watched the fireworks from a distance.
In Nigeria, crowds gathered to watch fireworks at the beach in the city of Lagos.
And of course, the revelers were ready to ring in the new year with parties in Brazil.
Revelers in Cape Town, South Africa, set off their own fireworks.
In New York City, people gathered at Times Square to watch the ball drop..
We will be updating this article as the clock strikes midnight in more countries.