Three strains of an unidentified Penicillium species were isolated during a fungal diversity survey of marine environments in Korea. These strains are described here as a new species following a multigene phylogenetic analyses of nuc rDNA internal transcribed spacer barcodes (ITS1–5.8S–ITS2), genes for β-tubulin, calmodulin and RNA polymerase II second largest subunit, and observation of macro-and micromorphological characters. Phylogenetic analyses revealed that the three strains formed a strongly supported monophyletic group distinct from previously reported species of section Aspergilloides . Morphologically this species can be distinguished from its sister species, P. crocicola , by the reverse color on Czapek yeast autolysate agar, abundant production of sclerotia on malt extract agar and colony characters on yeast extract sucrose agar. We name this new species P. jejuense , after the locality where it was discovered. At 25 C for 7 d, P. jejuense colonies grew to 55–60 mm on CYA, 45–48 mm on MEA, 48–52 mm on YES and 23–26 mm on CREA. Conidia (2.2–3.4 × 2.0–2.6 μm) and sclerotia (160–340 × 125–210 μm) were globose to ellipsoidal.