Here's a look at how people are celebrating the end of 2018 and the beginning of 2019.
The Pacific island nation of Kiribati was the first in the world to ring in the new year. In the capital Tarawa, many celebrated with church services and mostly quiet private events.
In Auckland, New Zealand, tens of thousands of people gathered around the 328-meter Sky Tower to watch a fireworks show. In other places, huge crowds gathered on beaches and streets as fireworks went off above city centers and seaports.
An estimated one million people crowded the Sydney Harbor, as Australia's largest city began the new year with a memorable fireworks celebration. More than 1 billion people around the world were expected to watch the fireworks on television. This year's fireworks show was one of the most complex in Australia's history.
North and South Korea
Thousands of South Koreans were expected to fill the streets of the capital Seoul for a traditional bell ringing ceremony near City Hall.
And North Korean leader Kim Jong Un is expected to give his yearly address on New Year's Day. In his New Year's speech last year, Kim spoke of talks with South Korea to reduce tensions and said the North would be willing to take part in South Korea's Winter Olympics.
New Year's Eve is not celebrated widely in mainland China. The lunar New Year in February is a more important holiday. But countdown events were being held in major cities.
Beijing held an event with important guests at the main site of the 2008 Summer Olympics. The event looked ahead to the 2022 Winter Games, which will also be held in the Chinese capital.
In Hong Kong, the city's tallest building was brightly lit. There also was a show of fireworks, music and lights over Victoria Harbor. About 300,000 people were expected to gather along the port.
Hundreds of Thais traveled to a Buddhist religious center near the capital Bangkok to lie inside coffins for traditional funeral rituals. Those who take part believe the ceremony removes bad luck and permits them to be born again for a fresh start in the new year.
New York City
Famous musicians and people from all over the world will gather in Times Square in New York City to welcome 2019.
Watchers are expected to start gathering early in the afternoon Monday. The celebration will take place under strict security, as people wait for the traditional midnight crystal ball drop.
I'm Jonathan Evans.