Micropholcus Deeleman-Reinhold & Prinsen, 1987 is one of only two Pholcidae genera known to occur both in the Old and New Worlds. However, there are major morphological and ecological differences among geographically separate groups of species, and it was mainly molecular data that have resulted in our current view of uniting all these species into a single genus. In the Old World, only four species have previously been described. Here, current knowledge about Old World Micropholcus is reviewed, redescribing three of the four previously known species, and describing twelve new species, originating from Saudi Arabia (M. dhahran Huber, sp. nov., M. harajah Huber, sp. nov., M. alfara Huber, sp. nov., M. abha Huber, sp. nov., M. tanomah Huber, sp. nov., M. bashayer Huber, sp. nov., M. maysaan Huber, sp. nov.), Oman (M. darbat Huber, sp. nov., M. shaat Huber, sp. nov.), Morocco (M. ghar Huber, sp. nov., M. khenifra Huber, Lecigne & Lips, sp. nov.), and the Philippines (M. bukidnon Huber, sp. nov.). We provide an exploratory species delimitation analysis based on CO1 barcodes, extensive SEM data, and first records of Acroceridae (Diptera) larvae in Pholcidae, extracted from book lungs.