He arrives on a free transfer from Genoa and has signed a contract until June 2012.
Toni said: “I am delighted. It's a dream come true.
“I really wanted to join the club. I actually turned down [more] money to accept their offer. I have come here to show my worth, which is something I am convinced about, as well as to try and score goals, which I have always done.
“I was excited when this offer was made to me. I know the group and I know of their desire to win. Last year with Roma we were a step away from realising a dream. I would like to bring a little bit of that luck with me and I believe [we can fight for the Scudetto] right until the end.
“I am ready to play against Napoli. It's up to the Coach to decide. It would be great to play alongside Alessandro Del Piero. He is a great champ.
“This group of players has a great hunger to get important results and therefore I am convinced that we will fight to win all the remaining games and hopefully get back to being the Juventus of old.
“You can't say no to Juve. I am a box-playing centre-forward and I believe that I will fit in well with Del Neri. I have chosen the No 20 shirt,