The bout will be formatted across eight rounds lasting three minutes each with 10-ounce gloves at Florida's Kaseya Center.
It is a replacement fight for Paul, who was set to square off with Gervonta Davis earlier this month, but that was cancelled after his opponent was named in a civil lawsuit.
"This isn't an AI simulation. This is Judgment Day," Paul said.
"A professional heavyweight fight against an elite world champion in his prime. When I beat Anthony Joshua, every doubt disappears, and no one can deny me the opportunity to fight for a world title.
"To all my haters, this is what you wanted. To the people of the United Kingdom, I am sorry. On Friday, December 19th, under the lights in Miami, live globally only on Netflix, the torch gets passed and Britain's Goliath gets put to sleep."
For Joshua, the fight will signal his return for the first time since his knockout defeat in his IBF title bout against Daniel Dubois in September 2024.
The 2012 Olympic Gold medallist chose to have elbow surgery following the loss, and his promoter, Eddie Hearn, promised he would return to the ring before the end of 2025.
"I took some time out and I'm coming back with a mega show," Joshua said.
"It's a big opportunity for me. Whether you like it or not, I'm here to do massive numbers, have big fights and break every record whilst keeping cool, calm and collected.
"Mark my words, you'll see a lot more fighters take these opportunities in the future. I'm about to break the internet over Jake Paul's face."