AbstractNumerous new taxa and classifications of Dothideomycetes have been published following the last monograph of families of Dothideomycetes in 2013. A recent publication by Honsanan et al. in 2020 expanded information of families in Dothideomycetidae and Pleosporomycetidae with modern classifications. In this paper, we provide a refined updated document on orders and familiesincertae sedisof Dothideomycetes. Each family is provided with an updated description, notes, including figures to represent the morphology, a list of accepted genera, and economic and ecological significances. We also provide phylogenetic trees for each order. In this study, 31 orders which consist 50 families are assigned as ordersincertae sedisin Dothideomycetes, and 41 families are treated as familiesincertae sedisdue to lack of molecular or morphological evidence. The new order, Catinellales, and four new families,Catinellaceae,Morenoinaceae NeobuelliellaceaeandThyrinulaceaeare introduced. Seven genera (Neobuelliella,Pseudomicrothyrium,Flagellostrigula,Swinscowia,Macroconstrictolumina,Pseudobogoriella, andSchummia) are introduced. Seven new species (Acrospermum urticae,Bogoriella complexoluminata,Dothiorella ostryae,Dyfrolomyces distoseptatus,Macroconstrictolumina megalateralis,Patellaria microspora, andPseudomicrothyrium thailandicum) are introduced base on morphology and phylogeny, together with two new records/reports and five new collections from different families. Ninety new combinations are also provided in this paper.