The Turin giants won Serie A last season for the first time since gaining promotion from the Italian second division and will feature in Europe's premier club competition once again.
Real Madrid and Barcelona will begin the campaign as favourites to win the Champions League, but Buffon is confident that Juve can challenge the top sides despite coach Antonio Conte's 10-month ban.
"When you play for a side like Juve you have the ambition and aspirations to try to win everything," said the 34-year-old.
"[Playing in the Champions League is] the right reward for a side who last season achieved something great. It is normal that the fans dream of success, just as much as it is normal for players and staff to remain grounded.
"[However] It's a different environment with respect to last year, there's more positivity and belief around the place now."
Juventus will begin their 2012-13 Serie A campaign with a home game against Parma on Saturday, August 25.