Silva was playing for Manchester City at the time when he made the comments about the two legendary forwards.
He told AS (via SportsMole):
"I prefer those two (Messi and Ronaldo), they are such great players and they are at the highest level, but I think Messi is the best. He shows every weekend that he is above the rest."
There is much debate over which of the two iconic attackers is the greatest of all time but Silva sided with the Argentinian.
Messi has won seven Ballons d'Or during his career to Ronaldo's five.
However, the Paris Saint-Germain forward has not been nominated for the prestigious award this year, whilst the Manchester United striker has.
Silva never came up against the Portuguese ace during his time at the Etihad Stadium.
The Spaniard departed City in 2020 whilst Ronaldo didn't make his groundbreaking return to United until 2021.
The pair did lock horns in Thursday's (September 8) UEFA Europa League opener and it was Silva's Sociedad who got the better of United winning 0-1.
Cristiano Ronaldo's performance was under scrutiny, with the Portuguese having been dropped to the bench by Erik ten Hag in each of the Red Devils' last four outings.
His absence as a starter has resulted in four wins on the bounce but his return to the starting XI against the La Liga side has coincided with a 1-0 defeat.
The former Real Madrid forward is yet to score or assist this season.
Meanwhile, Lionel Messi has flourished for PSG at the start of the season. The Argentine has managed an impressive four goals and six assists in eight appearances.
Manchester City's new signing Erling Haaland beats Cristiano Ronaldo and Lionel Messi record
Silva has unfortunately not been able to be part of the current City side that possesses one of Europe's deadliest strikers.
Erling Haaland arrived at the Etihad from Borussia Dortmund for £54 million and has had no problem adapting to life with the Cityzens.
The Norwegian hitman has now beaten the records set by both Lionel Messi and Cristiano Ronaldo in the Champions League.
Haaland now has the highest number of goals by a player in their first 20 appearances in the competition at 25.
Cristiano Ronaldo may hold the all-time record for the number of goals scored in the competition at 140.
But the United forward didn't manage to score a single goal in his first 20 appearances.
Meanwhile, Lionel Messi managed eight goals in his first 20 appearances and it just shows the incredible start to the season Haaland has managed.