Argentina are bidding to become the first team in 64 years to successfully defend the World Cup, while Spain are chasing their second title after winning the tournament for the first time in 2010.
More than 80,000 spectators, including US president Donald Trump, are expected at MetLife Stadium in East Rutherford for the final of the biggest World Cup in history.
World Cup officials said they are "monitoring closely" air quality from Canadian wildfires affecting the area around the final, which kicks off at 3pm local time (1900 GMT).
The final will also feature a 25-30 minute half-time show in the style of the Super Bowl, with performances by Madonna, Shakira and Justin Bieber.
Attention, however, will be on the pitch as Europe and South America meet for football's biggest prize.
Argentina fight back to end England's World Cup dream
Messi, 39, is expected to play the final World Cup match of his career. Widely regarded as one of the greatest players in football history, he will become only the second player to appear in three World Cup finals, matching Brazil's Cafu, who played in the 1994, 1998 and 2002 finals.
Messi has scored eight goals during Argentina's run to the final and is on course to win the Golden Boot.
The eight-time Ballon d'Or winner has also played a key role in keeping Argentina's World Cup campaign alive.
He inspired Argentina's comeback win over Egypt in the last 16 after they trailed 2-0 with 11 minutes remaining before winning 3-2.
He then provided two assists in Wednesday's 2-1 semi-final victory over England in Atlanta.
The win reflected the resilience of Lionel Scaloni's side, who have won back-to-back Copa America titles either side of their 2022 World Cup triumph.
Scaloni said his players' mentality had been central to their success.
"This group is difficult to explain," he said. "It is a show of the collectiveness, the brotherhood that we are in, the willingness to fight to the very end.
"I know the guys. They fear nothing."
Argentina now face what could be their toughest test of the tournament.
Spain gathered momentum as the competition progressed before beating France 2-0 in the semi-finals.
The result highlighted the strengths of Luis de la Fuente's side, who controlled France with their possession-based style.
Spain's midfield of Rodri, Fabian Ruiz and Dani Olmo dominated the game before creating the chances that led to the goals.
Spain have also had the strongest defence in the tournament, conceding only one goal while keeping six clean sheets in seven matches.
Another clean sheet in the final would see Spain set the record for the fewest goals conceded by a World Cup-winning team.
In attack, Lamine Yamal could play a key role.
The 19-year-old Barcelona winger, who starred in Spain's European Championship triumph two years ago, has yet to reach his best form in this tournament as he continues his recovery from a hamstring injury.
However, he showed signs of his quality against France, winning the penalty that gave Spain the lead and having what would have been a third goal ruled out for a marginal offside.
The final will also see Spain coach Luis de la Fuente come up against Argentina boss Lionel Scaloni, whom he coached while Scaloni was studying for his professional licence in 2018.
De la Fuente, 65, became Spain coach in 2022 after working with the country's youth teams.
Scaloni, 48, who lives in Spain and has close personal and professional ties to the country, said he would put that friendship aside for the final.
"He was my mentor, and he taught me everything I know and now we are facing each other in a final," Scaloni said of de la Fuente.
"Everyone knows I live in Spain and have Spanish family. And I'm very, very sorry, but on Sunday I'm going to try to beat him."
(With inputs from agencies)
