Chilean midfielder Vidal will be presented on Monday following his arrival from Bundesliga champions Bayern.
Speaking for the first time as a Barca player, Vidal – who replaces Paulinho after the Brazilian returned to Guangzhou Evergrande – said: "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.
"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.
"[I will bring] a lot of fight, lots of passion, helping the team at all times, and making sure the team always wins.
"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."