The two La Liga stars are expected to go head to head in this weekend's first El Clasico of the league season at the Bernabeu.
Ronaldo may currently be in possession of the coveted Ballon d'Or, but Suarez is adamant that Messi, who is a four-time winner of the gong, is at the top of an elite pile.
"In my opinion Leo is better," The Mirror quotes Suarez as saying. "I train and play with Leo every day and he surprises me every day. He is unique.
"Everybody knows what he has brought to Barcelona, what kind of world-class player he is. For me he is the best player in the world for what he has already done, and he's still so young."
Suarez is eligible to play his first game for Barcelona at the weekend after serving a four-month ban for biting.