France's Paire shook off a tentative start to sail past American Steve Johnson 1-6, 6-0, 6-0 in the semi-finals.
Hurkacz, the third seed from Poland, downed second-seeded Canadian Denis Shapovalov 6-3, 6-4.
All four of the semi-finalists pulled double-duty on Friday after thunderstorms and an electrical outage caused the quarter-finals to be postponed from Thursday.
Paire beat Spain's Pablo Carreno-Busta 7-6 (7/5), 1-6, 6-3 in the quarters.
Hurkacz defeated American Frances Tiafoe 4-6, 7-6 (7/1), 6-1.
Shapovalov beat Russian Andrey Rublev 6-3, 7-6 (7/4) while Johnson defeated Australian John Millman 4-6, 7-6 (7/5), 6-4.
With the US Open starting on Monday, Paire admitted he was a little rattled to feel discomfort from an upper leg muscle injury during his match against Carreno-Busta.
But when his game started clicking in the third set, he said, "it started feeling better."
The momentum didn't carry over into his semi-final against Johnson, when he was "not feeling very well" to start the match.
"Steve was playing at a good level. So it was not easy, but after I was feeling better, I served better so it was important to stay with myself," Paire said.
"I was moving very well, and I'm really happy about my win today because it's my third final of the year," added Paire, who won in Marrakesh and Lyon.
Both of those titles were on clay. Saturday's match will mark his first outdoor hardcourt final and his first in the United States.
"It's my first on a hard court, so honestly it's a good opportunity for me, and a week before the US Open is very important," he said.