UFC 244: Masvidal vs. Diaz was a mixed martial arts pay-per-view event produced by the Ultimate Fighting Championship that took place on November 2, 2019 at Madison Square Garden in New York City, New York, United States. It was the UFC's 500th live event.

Nathan Donald Diaz is an American mixed martial artist and professional boxer who is currently a free agent. Diaz is most known for his time spent fighting in the Ultimate Fighting Championship (UFC), where he fought for over 15 years after winning The Ultimate Fighter 5. Prior to signing with the UFC, Diaz competed in World Extreme Cagefighting, Strikeforce, and Pancrase. Diaz has the third most UFC bonus awards, with 16 in total.