According to the folks over at the Guinness World Records, the largest circular pizza ever baked was made by NIPfood at Fiera Roma, in Rome, Italy by five Italian chefs on December 13, 2012. It measured 131 feet in diameter ... and tipped the scales at over 51,000 pounds!
Dovilio Nardi, Andrea Mannocchi, Marco Nardi, Matteo Nardi and Matteo Giannotte prepared the 100% gluten-free pizza named "Ottavia", a word of Roman origin for "eighth son", as a homage to the first Roman emperor Octavian Augustus.
The data is a bit sketchy, but here are relevant numbers:
19,800 lbs. of Flour
10,000 lbs. of Tomato Sauce
551 lbs. of Salt
8,800 lbs. of Mozzarella Cheese
1,488 lbs. of Margarine
Is there video? Yes, there's a video: