Cristiano Ronaldo and Lionel Messi are the best players in FIFA 21. They're commonly accepted as the two best footballers of their generation, and they've also been the two highest-rated players in the FIFA series since 2011. In FIFA 21, Messi is one point higher than Ronaldo, but they're both down a point since last season. Messi is the highest player in the game, at 93 OVR, and Ronaldo is the only player with a 92 OVR rating. Both players are outstanding goalscorers in FIFA 21, but they each have their strengths and weaknesses.
Messi and Ronaldo have been the top two players in FIFA for a whole decade now. Messi had always been rated higher, typically given a rating of 94. Cristiano Ronaldo was always second, usually one point behind Messi, until FIFA 17 when they switched and Ronaldo was given the 94 rating to Messi's 93. Then, in FIFA 18 and 19, they were both given a 94.
Last year, FIFA's Ronaldo fell back to a 93 and left Messi on top. Ronaldo changed teams last season, and isn't playing with the Galacticos at Real Madrid anymore. Messi is still on Barcelona, but that team isn't what it used to be either. Both players have less support than in previous years, both in real life and in FIFA, so their overall teams may not be as dominant.
How FIFA 21's Ronaldo & Messi Play
In previous years, Real Madrid and Barcelona were the top two teams in the game, no questions asked. Now that Ronaldo is at Juventus, he's got less help in midfield and defense. Juventus is still a top five team in the world, and Italy's best, but without Ronaldo they're just a collection of B+ players. Barcelona, on the other hand, has star power. They've got 87 OVR Griezmann, a 90 OVR GK, and a highly-rated defense. It's an ageing team, so this might be the last great Barcelona side with Messi as their crown jewel.
Both players have completely different styles of attacking the goal. Ronaldo used to be a winger with tons of pace and skill moves, but now he's more of a poacher, scoring headed goals or taking long-range shots. Messi doesn't have 5-star skill moves like Ronaldo, but he does have superior dribbling and free-kick ability. He's more of a Volta player, a mode included in FIFA 21. What this means is that Ronaldo is more dependent on a strong squad around him, whereas Messi can drag a team further on his back.
When players are using a different team in FIFA 21's career mode and trying to acquire Messi or Ronaldo, Messi is most likely the best option. He's a better passer, can score free kick goals with ease, and is just a smidge quicker. However, Ronaldo would be the best addition to an Ultimate Team already full of star players. To unlock Ronaldo, his team needs a speedy winger who can cross the ball, which Juventus don't have. Once he's unlocked, Ronaldo is a 50-goal/season monster with a signature celebration. But 1v1, FIFA has always crowned Lionel Messi as the best footballer in the world.