Children are counting down the hours until Christmas morning.
But for some people around the world, Santa has already been.
According to experts in the know, the big man - accompanied by Dasher, Dancer, Prancer, Vixen, Comet, Cupid, Donner, Blitzen and Rudolph - had delivered more than 730,000 presents by 1pm GMT.
And if you want to see where he will be next on his travels you can do just that using North American Aerospace's Defense Command's (NORAD) Santa tracker.
Where is Santa right now?
At the time this article was written, (1.30pm), Santa was flying over Australia.
He has already delivered millions of gifts.
Santa has also already visited New Guinea, check out that view.
How do they track Santa?
According to NORAD, they track Santa using infrared sensors from Rudolph's nose.
NORAD also reports that Santa is getting weather information from his elves.
There's a chance that anyone awake as Santa enters UK airspace could glimpse his sleigh and perhaps spot that famous red-nosed reindeer.
How fast does Santa travel?
With a total route of more than 300,000,000 miles Santa needs to move quickly. NORAD estimates he's moving at 1,800 miles per second.
How many houses does Santa visit?
Santa needs to hit 390,000 homes per minute to hit his target. In total he's going to around 75 million houses over Christmas night. Thank goodness he's been getting years of practice.
How do I find out where Santa is?
Well, if you fancy making an international call then the NORAD hotline is 00-1-719-556-5211.
You can track him online using the official NORAD Tracks Santa website .
You can also email noradtrackssanta@outlook.com to find out where the big man is currently.
There are also apps for both Android and iOS that will help you keep tabs on Santa.
What is NORAD?
NORAD is the North American Aerospace Defense Command, the organisation responsible for monitoring Canadian and US airspace.
Although mostly intended to detect threats to the US from air attacks, NORAD is well-placed to keep an eye out for Santa and as such can reassure children that he is both on his way to their house, and being kept safe.
NORAD said that as long as Santa entered US airspace it had a responsibility to track his festive activities and those of every other aircraft over North America.
