Alcaraz lost his opening set at Queen’s earlier in the week but has since looked ominously good and proved too powerful for Korda, winning 6-3, 6-4.
Should Alcaraz win Sunday’s final he would reclaim the world No.1 ranking from Novak Djokovic and would be seeded 1 at Wimbledon, which begins July 3.
Korda, 22, was at full stretch to try and keep Alcaraz at bay in the opening set but still dropped serve twice, although he did also manage to break the Spaniard.
Alcaraz, 20, began to unleash some heavy groundstrokes and showed plenty of grass-court acumen despite being a relative novice on the surface. He forged an early break ahead in the second set and never looked in danger from that point on.
Fellow 20-year-old Rune had not dropped a set on the way to the semifinals but found the livewire De Minaur a step too far as he fell short of also reaching his first final on grass.
World No. 18 De Minaur, who put out home favorite Andy Murray earlier in the week, is aiming for his second career title on grass having won at Eastbourne in 2021.
He is the first Australian to reach the final at the Queen’s pre-Wimbledon event since Lleyton Hewitt in 2006.
Two breaks of serve allowed the seventh seed to cruise through the first set but he was pushed much harder in the second with both players forced to save break points.
However, De Minaur’s greater experience on the slick lawns showed as he polished off the tiebreak.
“I play pretty decent on the grass, I love playing on this court,” he said. “Today was my best match so far this week. I just hope that I can go one better tomorrow.”
Carlos Alcaraz into Queen’s Club final; No. 1 rank in reach