(Note: I'm going to be using the British English "ladybird" instead of the US English "ladybug" in this answer.)
This is a clearly a species of ladybird. Going by the number of spots, their size and not-perfectly-round shape, the positioning of the four central spots relative to the others, and the fact that its background colour isn't bright yellow... I'm pretty sure it's Harmonia axyridis, the species that us Brits refer to as a "Harlequin ladybird". I think Americans refer to it as an "Asian ladybug" or "Asian ladybeetle".
The spot patterns for this particular species vary a lot, as to some extent do the colours, so I've googled for images to support this answer. The below picture was posted to:
and is the IP of a user or organisation called Entomart. On the Wikipedia page and on their homepage, Entomart grant permission for the use of the image as long as they are given proper attribution, so I'm able to include it in this answer:
For more pictures of the Harlequin (again, showing how much the spot pattern and colouration vary), see:
For pictures of other ladybird species to compare the Harlequin with - as also one more of the Harlequin:
Thanks for posting this question! I didn't expect to see a ladybird on Christmas Day :-)