I'm not sure why I didn't come across this sooner, but today is the day I learned about IUCN's list of the 100 Worst Invasive Species. Not surprisingly, there are some fungi (and two fungus-like protistans) on there, though not as many as I might have thought. They list five species, of which I would have guessed that four of them. Reflecting their bias towards macroorganisms, there are NO bacteria on the list, but two viruses (which are not even alive, in my well-supported opinion) and one non-funguslike protist (the avian malaria pathogen, Plasmodium relictum, an apicomplexan). Also, the invasives are bad because they are disease agents of larger, more charismatic eukaryotes. They do indicate that the criteria for selection includes "serious impact on biodiversity and/or human activities".
Their five fungi and funguslike organisms?
Cryphonectria parasitica (Ascomycota), causal agent of chestnut blight
Ophiostoma ulmi (Ascomycota), causal agent of Dutch elm disease
Batrachochytrium dendrobatidis (Chytridiomycota), causal agent of frog
Phytophthora cinnamomi (Oomycota), causal agent of Jarrah dieback etc.
Aphanomyces astaci (Oomycota), causal agent of crayfish plague
The last of these, I had never heard of before. I'd heard of the genus before, but I'd forgotten that it's an oomycete genus. The IUCN describes these as "macrofungi", though I would say none of them really are, except the pycnidia and perithecial stromata of C. parasitica are visible to the naked eye.