Noteworthy records of forty-three lichens and allied fungi are presented based on recent collections from Ontario, Canada. Three species, Agonimia borysthenica, Arthonia subconveniens (on Ricasolia quercizans) and Lecanographa abscondita are reported for the first time from North America. Eleven species, Erythricium aurantiacum (on Physcia millegrana), Hypotrachyna showmanii, Leptogium arsenei, Opegrapha rupestris (on Bagliettoa), Pronectria tibellii (on Cladonia pocillum), Punctelia missouriensis, Thelidium zwackhii, Tremella imshaugiae (on Imshaugia aleurites), Verrucaria bryoctona, Vezdaea schuyleriana and Vouauxiella lichenicola (on Lecanora) are reported for the first time from Canada. Eleven species, Absconditella sphagnorum, Agonimia gelatinosa, Didymocyrtis xanthomendozae (on Xanthomendoza hasseana), Distopyrenis americana, Lichenochora obscuroides (on Phaeophyscia pusilloides and P. sciastra), Paranectria oropensis (on Lecanora and P. rubropulchra), Pertusaria sommerfeltii, Raesaenenia huuskonenii (on Bryoria fuscescens), Stereocaulon depreaultii, Thrombium epigaeum and Trichonectria rubefaciens (on Aspicilia) are reported as new to Ontario. Details on 18 additional rare or otherwise rarely collected species new to various counties and districts of the province are also provided. These include: Abrothallus microspermus (on Flavoparmelia caperata), Ahtiana aurescens, Athelia arachnoidea (on Physcia millegrana), Blennothallia crispa, Chaenothecopsis brevipes (on Inoderma byssaceum), C. rubescens (on I. byssaceum), Cladonia dimorphoclada, Corticifraga fuckelii (on Peltigera evansiana), Didymocyrtis cladoniicola (on Cladonia), Hypotrachyna revoluta, Lepra panyrga, Marchandiomyces corallinus (on Parmelia squarrosa and Physcia thomsoniana), Muellerella hospitans (on Bacidia rubella), Refractohilum peltigerae (on Peltigera evansiana), Reichlingia leopoldii, Sarcosagium campestre, Steinia geophana and Vezdaea acicularis. Appalachian-Great Lakes Region, biogeography, florsitics, North America, range extensions, rare species