The Netherlands international admits that he was stunned when he was told of the Catalan club's interest but has now set his sights on Champions League glory at Camp Nou
The Netherlands goalkeeper joined the Catalan giants last week, replacing Claudio Bravo, who joined Manchester City.
And as he settles into life at Camp Nou, Cillessen has revealed that he was stunned when he was told of the Liga club's interest.
"When my agent told me [about Barcelona's interest] I asked him if it was a joke," Cillessen told Barca TV.
"[I couldn't believe that] the best club in the world was interested in me."
Now, as he vies for the number one role with Marc-Andre ter Stegen, Cillessen has set his sights on Champions League glory.
"I want to win titles at Barcelona and I would like to be the goalkeeper that wins the Champions League as a starter," the 27-year-old added.