Three new genera, six new species, three combinations, six epitypes, and 25 interesting new host and / or geographical records are introduced in this study. New genera: Neoleptodontidium (based on Neoleptodontidium aquaticum), and Nothoramularia (based on Nothoramularia ragnhildianicola). New species: Acremonium aquaticum (from cooling pad water, USA, Cladophialophora laricicola (on dead wood of Larix sp., Netherlands), Cyphellophora neerlandica (on lichen on brick wall, Netherlands), Geonectria muralis (on moss growing on a wall, Netherlands), Harposporium illinoisense (from rockwool, USA), and Neoleptodontidium aquaticum (from hydroponic water, USA). New combinations: Cyphellophora deltoidea (based on Anthopsis deltoidea), Neoleptodontidium aciculare (based on Leptodontidium aciculare), and Nothoramularia ragnhildianicola (based on Ramularia ragnhildianicola). Epitypes: Cephaliophora tropica (from water, USA), Miricatena prunicola (on leaves of Prunus serotina, Netherlands), Nothoramularia ragnhildianicola (on Ragnhildiana ferruginea, parasitic on Artemisia vulgaris, Germany), Phyllosticta multicorniculata (on needles of Abietis balsamea, Canada), Thyronectria caraganae (on twigs of Caragana arborescens, Ukraine), and Trichosphaeria pilosa (on decayed Salix branch, Netherlands). Furthermore, the higher order phylogeny of three genera regarded as incertae sedis is resolved, namely Cephaliophora (Ascodesmidaceae, Pezizales), Miricatena (Helotiales, Leotiomycetes), and Trichosphaeria (Trichosphaeriaceae, Trichosphaeriales), with Trichosphaeriaceae being an older name for Plectosphaerellaceae. Citation: Crous PW, Akulov A, Balashov S, Boers J, Braun U, Castillo J, Delgado MA, Denman S, Erhard A, Gusella G, Jurjević Ž, Kruse J, Malloch DW, Osieck ER, Polizzi G, Schumacher RK, Slootweg E, Starink-Willemse M, van Iperen AL, Verkley GJM, Groenewald JZ (2023). New and Interesting Fungi. 6. Fungal Systematics and Evolution 11: 109-156. doi: 10.3114/fuse.2023.11.09.