This paper deals with the 185 new species-group taxa that P. J. M. Macquart described in the dipteran families Fanniidae, Anrfiomyiidae and Muscidae, together with a further 5 species-group taxa that belong to other families, 9 replacement names that he proposed, and 1 nomen nudum. Notes are provided on the Diptera collections on which Macquart worked. In the Fanniidae, there are 8 species (and 1 replacement name), in Anthomyiidae, 33 species (and 4 replacement names), and in Muscidae, 144 species (and 4 replacement names). 85 lectotypes are newly designated in order to fix the identity of the names. The following new synonyms are proposed: in Anthomyiidae: Chortophila angusta Macquart, 1835 = Botanophila striolata (Fallén, 1824); Pegomyia basilaris Macquart, 1835 = Pegomya solennis (Meigen, 1826); Anthomyia brunnipennis Macquart, 1835, and Anthomyia fuscipennis Macquart, 1835 = Pegoplata aestiva (Meigen, 1826); Hylemyia caesia Macquart, 1835 = Anthomyia liturata (Robineau-Desvoidy, 1830); Chortophila caesia Macquart, 1835, and Anthomyia fulviceps Macquart, 1835 = Delia platura (Meigen, 1826); Chortophila cuprea Macquart, 1835, and Nerina cinerea Robineau-Desvoidy, 1830 = Adia cinerella (Fallén, 1825); Chortophila geniculata Macquart, 1835 = Emmesomyia grisea (Robineau-Desvoidy, 1830); Hydrophoria liturata Macquart, 1835 = Zaphne ambigua (Fallén, 1823); Pegomyia nigrifrons Macquart, 1835 = Pegomya rufina (Fallén, 1825); Hylemyia nitida Macquart, 1835 = Chirosia flavipennis (Fallén, 1823); Anthomyia tibialis Macquart, 1835 = Pegomya conformis (Fallén, 1825); Anthomyia vicina Macquart, 1835 = Botanophila fugax (Meigen, 1826). In Muscidae: Caenosia basilaris Macquart, 1835 = Caenosia testacea (Robineau-Desvoidy, 1830); Lucilia brevigaster Macquart, 1835 = Neomyia timorensis (Robineau-Desvoidy, 1830); Pyrellia desjardinsii Macquart, 1843 = Neomyia viridifrons (Macquart, 1843); Aricia latipennis Macquart, 1843 = Dimorphia tristis (Wiedemann, 1819); Pyrellia violacea Macquart, 1851 = Neomyia diffidens (Walker, 1856). In Calliphoridae: Lucilia rectinevris Macquart, 1855 = Hemipyrellia ligurriens (Wiedemann, 1830). One new combination is proposed: Chrysomya flavidipennis (Macquart, 1843), in Calliphoridae.