Djokovic, the 24-time Grand Slam champion, is without a major title since 2023, where he lifted the trophy in New York, New York, defeating Daniil Medvedev in the final.
Since then, the new guard has asserted its dominance, with Jannik Sinner and Alcaraz hoarding the last year’s Slams.
Alcaraz is a five-time Grand Slam winner and the current French Open holder, but his two-year winning streak at Wimbledon was ended by Sinner in July.
Sinner, the world No1, is the defending champion at Flushing Meadows having beaten home favourite Taylor Fritz in last year’s final.
The Italian takes on Canadian Felix Auger-Aliassime in the other last-four match, but before them, Djokovic and Alcaraz lock horns on Arthur Ashe Stadium for a ninth time.
The Serb is up 5-3 in the pair’s head-to-head, and has won the last two meetings between them, at the Paris 2024 Olympics gold medal match, and in this year’s Australian Open quarter-finals.
From those two matches, Djokovic has dropped just one set, and on hard courts, he is unbeaten against the 22-year-old Spaniard.
Alcaraz, however, has winning pedigree at the US Open, claiming a first major title of his nascent career in 2022.
The second seed is yet to drop a set at this year’s tournament, and he put on a spectacular show as he breezed past 20th seed Jiri Lehecka in the last eight.
Djokovic, meanwhile, survived two scares in the second and third round, dropping a set each to Zachary Svajda and Cameron Norrie, and he recovered from a third-set blip against world No3 Fritz to come through the American in four sets in the quarter-finals.
How to watch Novak Djokovic vs Carlos Alcaraz
TV channel: You can watch this match – and the whole of the US Open – on Sky Sports Tennis, with this match estimated to get underway at around 8pm BST.
Live stream: Those with Sky Go or Now TV sport subscriptions can also stream the semi-final clash live.
