Sinner was made to work for a 6-4 7-6 (7-3) semi-final victory against Zhang Zhizhen on Saturday, but it got the Australian Open champ to a maiden final on the green stuff.
His best previous result on the surface was a semi-final last year at Wimbledon, which he lost to Novak Djokovic.
"It means a lot. I had four very tough matches to go to the final," he said.
"It was a good match. Definitely more rallies than yesterday and that's exactly what I needed today. I'm happy and let's see what's coming tomorrow."
Sinner will meet fifth-seeded Hurkacz, who defeated Olympic champion Zverev 7-6 (7-2) 6-4.
Hurkacz, who won the Halle title in 2022, produced an impressive serving display in the semi-final, firing 17 aces and saving all four break points he faced to earn his fifth top-10 grass-court win.
"It needed to be really good," Hurkacz said. "He is such a good competitor and is playing good tennis, reaching the final at the French Open and playing at a really high level.
"I am really confident on my serve. I am serving really good. There were some moments but I managed to believe in my game and hit some good serves and good shots, so I stayed pretty calm."
Germany's Zverev was seeking his first trophy in Halle, after having advanced to the title match on home soil in 2016 and 2017.
