The Spaniard booked his place in the Flushing Meadows showpiece with a comfortable straight-sets victory over Richard Gasquet, hours after Djokovic defeated Stanislas Wawrinka in the other semi-final.
After an 18-month spell during which he was hampered by injuries, Nadal has recaptured his best form in New York and is in great spirits ahead of his clash with Djokovic on Monday.
"It has been two amazing weeks for me," he told reporters. "Novak is an amazing competitor he is one of the best players I have ever seen.
"He is a great champion, it will be a tough final for me but I will try and be ready."
Nadal has one US Open title to his name, courtesy of his victory over Djokovic in the 2010 final.