The 31-year-old joined the Catalan giants from Bayern Munich in a move worth €20million.
Vidal, who signed a three-year deal, is eager to get started with his new teammates, which include Lionel Messi, Luis Suarez and Sergio Busquets.
"To be honest I am very happy. I am looking forward to starting training with my team-mates, to wearing such a famous shirt, and to doing important things here," Vidal said at the unveiling.
"It is a dream. I hope to achieve my objectives. I am here to win all the trophies available and I will give everything on the pitch to achieve this.
"A lot of fight, lots of passion, helping the team at all times, and making sure the team always wins.
"Winning everything. During the three-year contract, I hope we can win everything we play for.
"I am excited to play with Messi, Suarez, Sergio Busquets … they are all great players."