A Messi-inspired Argentina booked their place in the final after overcoming Croatia 3-0 on Tuesday.
Messi opened the scoring with a penalty before Julian Alvarez added two more either side of half time.
Argentina will play the winner of Wednesday's second semi-final between France and Morocco on Sunday.
Messi equalled Lothar Matthaus' record of 25 world cup matches against Croatia and is set to break the record on Sunday.
The seven-time Ballon D'or winner also moved ahead of Gabriel Batistuta as Argentina's top scorer in the World Cup finals with 11 goals.
Messi is now a veteran of five World Cups and at 35 years of age, he reckons he might be too old to play in the next tournament in 2026.
"I am proud to be able to finish my World Cup journey playing this final," Messi told reporters. "What I'm experiencing is exciting. Sunday will be my last game in a World Cup.
"It will be many years before the next one [2026] and I don't think I'll be able to make it, so I hope I can finish in the best way."
"I'm enjoying it all very much," Messi said about the 2022 World Cup. "I feel good. I feel strong to face every game. We have been making a big sacrifice.
"The last game we played was with extra time. That was not easy at all. We were tired, but the group got strength. We played a very important game. We knew it was going to be the match it was.
"I'm very happy. Throughout this World Cup I've been having a lot of fun and, luckily, I was able to help the group to get things done."
Victory for Argentina on Sunday will cement Messi's legacy as arguably the greatest player of all-time.
