The 20-year-old Italian will wrap up the drivers' championship on Sunday if he wins the race, his Mercedes teammate George Russell finishes outside the top eight and Lewis Hamilton finishes outside the top four.
Antonelli secured his seventh pole of the season and his first in eight races with a fastest lap in 1min 34.035sec to outpace Max Verstappen, his nearest challenger, by 0.179sec with Verstappen's Red Bull teammate Isack Hadjar a career-best third.
Ferrari’s Charles Leclerc was fourth ahead of Russell, in the second Mercedes, and seven-time champion Hamilton in the second Ferrari.
Antonelli leads Russell by 102 points in the championship and is aiming to become Formula One's youngest champion and Italy's first since Alberto Ascari of Ferrari in 1953.
"We got pole so we'll try to win tomorrow," said Antonelli. "Max has been very quick and did an incredible job in qualifying so it's not going to be easy.
"Hopefully, we'll be leading into Turn One and we'll try to set the pace - even though it's going to be very tight.
"I'm very happy with qualifying, but Q3 was very tough with the wind, gusty and unpredictable, but I’m happy to stick it on pole."
Verstappen, who won this race from pole last year and will go in search of his fifth victory in Austin, said: "Q3 was not good. Q1, Q2 it was nice, but for whatever reason with both sets of tyres, I just didn't have the balance. No mistakes, but just no grip."
McLaren duo Oscar Piastri and reigning world champion Lando Norris qualified seventh and eighth ahead of Racing Bulls' rookie Arvid Lindblad, who has a five-place grid penalty, and Liam Lawson.
The session took place in hot and cloudy conditions, with the two Cadillacs leading out ahead of fellow Americans Haas before Leclerc clocked a marker time of 1 min 35.200 sec to set the pace ahead of Verstappen.
After seeing 207 laps deleted on Friday and 42 in final practice, all the drivers knew how important it was to avoid exceeding track limits in the qualifying hour – a problem that left Alpine's Pierre Gasly requiring a late lap, with seconds to spare, to survive the first qualifying session after losing his earlier time.
The top ten shootout began with Antonelli quickest on the opening runs ahead of the two Red Bulls and Leclerc back in fourth, Ferrari seemingly unable to find the progressive speed needed to stay on the pace of Mercedes and their young tyro.
As so often this year, the precocious Italian found the speed he needed as he prepared for his final run and delivered pole with his now customary elan.
