Jurgen Klopp's men currently sit second in the league table, trailing the Bavarians by just one point, and Hoeness thinks his side will face a tough task to shake off last year's runner-up.
"Dortmund have presented themselves just like we expected them to do. They are the toughest opponent we will have to beat this season," Hoeness told Sport Bild.
"Even if we cannot write off Bayer Leverkusen either, I have no doubt that the duel with Dortmund will last right until the end of the season."
Hoeness then went on to stress that Pep Guardiola's men can still win matches even if they're not on top form and stressed that he's confident FCB will be successful this term.
"The team showed against Hertha that they can also win games without playing 'tiki-taka'. We can also win matches by fighting for it.
"I am very optimistic about the remainder of the season."