The Poland international has scored 20 goals in the Bundesliga this season, making a major contribution to Dortmund's second consecutive title success and attracting interest of several top European clubs.
However, Klopp says the 23-year-old is going nowhere and Bayern would be wasting their time even trying to lure him to Munich.
"Who do they think we are?" he said. "He is not available.
"Do Bayern think that they can just come along and ask if 'Lewi' would like to play for them when Mario Gomez can't for some reason?
"That's a load of rubbish and can be ruled out."
Klopp was not so dismissive about Shinji Kagawa leaving the club, though.
The Japanese forward is being linked with moves to the Premier League and Klopp says he would not stand in his way were he to request a move.
"I would not be disappointed in the slightest," he told Sport Bild magazine.
"Shinji Kagawa has played two incredible years here and if he has dreamt of playing somewhere else and now he feels is the right time to do it, then we would say goodbye to him with the utmost respect and best wishes.
"But I don't believe he will leave, I think he will stay."