Phlegmacium brunneiaurantius is a species of fungus in the family Cortinariaceae.

[1] It was originally described in 2014 by the mycologists Ilkka Kytövuori, Kare Liimatainen and Tuula Niskanen who classified it as Cortinarius brunneiaurantium.

[2] In 2022 the species was transferred from Cortinarius and reclassified as Phlegmacium brunneiaurantium based on genomic data.

[3] Found only in south Finland, where it grows in deciduous forests, it was described as new to science in 2014.

Close relatives include C. sobrius, C. balteatus, C. brunneoviolaceus, C. pseudonaeovosus and C. clarobaltoides var.