First-half goals by Lautaro Martinez and Angel Di Maria put the south American champions in complete control against an Italy side who were back at Wembley 11 months after beating England to win the delayed Euro 2020.
With thousands of their supporters in the 87,000 crowd determined to turn northwest London into Buenos Aires for the night, an Argentina side including Lionel Messi was simply too quick and slick for the lumbering Azzurri.
"It was a beautiful final, full of Argentinians. What we've experienced here was beautiful. We knew it was going to be an attractive game and a nice setting to be champion," Messi said after the match. "We can compete against anyone. Today it was a good test because Italy is a great team."
Martinez tapped home from close range in the 28th minute from Messi's low cross to reward Argentina's early dominance.
"This is priceless. We are extremely happy for how things are going, for our play and for what this group is," Martinez said. "There are still several months to go before the World Cup and we know we need to correct certain things."
Inter Milan's Martinez then slid a pass through for Di Maria to double the lead with a dinked finish on the stroke of half-time to send the South American fans into raptures.
Argentina could have scored plenty more after the break with Messi pulling the strings and Italy keeper Gianluigi Donnarumma sparing his side a drubbing.
Substitute Paulo Dybala underlined Argentina's superiority with a drilled low finish in stoppage time.
It was a disappointing end to Italy stalwart defender Giorgio Chiellini's international career as the 37-year-old was substituted at half-time on his 117th and final appearance.
The Finalissima is the revival of the CONMEBOL-UEFA Cup of Champions that has been played only twice before, in 1985 and 1993.
Messi, who lit up the evening with a series of trademark dribbles, was hoisted into the air by his team mates who danced jigs of joy on the lush Wembley turf.
Argentina, who ended a 28-year wait for a trophy by beating Brazil to win the 2021 Copa America, produced a display that augurs well for their hopes at the Qatar World Cup this year, extending their unbeaten run to 32 games.
"Everything changed since we won the Copa America," Di Maria said. "We got rid of that weight and now we are enjoying playing, having a good time and things are much easier for us. We are enthusiastic, but we must always keep our feet on the ground."
For Italy, it was a sobering reminder of just how quickly fortunes can change in football.
Last July, Roberto Mancini's team were euphoric after a penalty shootout win over England to win the European Championship, but have since suffered the humiliation of failing to qualify for the World Cup for the second successive tournament after losing in a playoff to North Macedonia.
In the build-up Mancini described game as the "end of a cycle" and the defeat left him in no doubt as to how much work is required to revive Italy's fortunes.
"They were better than us. We were in the game in the first half but didn't do enough to turn it around after the break," Mancini said.