Coutinho will complete his £146m move from Liverpool today once the formalities are thrashed out, signing a five-and-a-half-year contract in a deal which will make him the second-most expensive player of all time.
"I'm very happy, very happy. I have always said that it is a dream that I am living and I am very happy to be here," Coutinho told Barca TV.
"To be able to play, win titles, make the fans happy... always play with joy. It is incredible to know that I am going to live with idols, players with a lot of history.
"Footballers like Leo Messi, Luis Suarez, Iniesta, [Gerard] Pique, [Sergio] Busquets. I am very happy to be able to live together, to be able to learn from them and be able to win together."
Coutinho could make his debut for Barcelona during the Copa del Rey clash with Celta Vigo on Thursday.