Joel Madden -- Booted From Australian Hotel ... FOR WEED

8:32 AM PT -- Madden just addressed the situation on Tumblr ... writing, "Sunday while I was at work, a hotel employee found a small amount of marijuana in my hotel room."

"The police were called and responded. Sydney is is [sic] my adopted home and i appreciate the way the NSW police handled the situation."

"They have informed me there will be no charges. I hope this didn't cause too much drama for anyone."

Good Charlotte member Joel Madden -- Nicole Richie's husband -- has been BOOTED from a hotel in Sydney, Australia on Sunday after officials say they found some pot in his room ... TMZ has learned.

According to police in New South Wales, Australia ... cops executed a search warrant at 10:30 pm Sunday night and seized a "small amount of plant matter believed to be cannabis."

Cops wouldn't say if the weed belonged to Madden -- but DID say a 34-year-old man was present during the search. FYI -- Joel is 34.

However, TMZ spoke with the manager of the Darling Hotel who did name names ... saying, "Joel Madden was ejected from the hotel because a small amount of cannabis was found inside his hotel room."

He added, "In Australia there is a 0 tolerance for this no matter where you are."