| Acaridae Latreille, 1802 | Acarid mites | 16 | Species | Taxom |
| Acherontacaridae Cook, 1967 | | 3 | Species | Taxom |
| Achipteriidae Thor, 1929 | | 14 | Species | Taxom |
| Aeroglyphidae Zakhvatkin, 1941 | | 1 | Species | Taxom |
| Agelenidae C. L. Koch, 1837 | Agelenid Spiders | 57 | Species | Taxom |
| Alloptidae Gaud, 1957 | | 3 | Species | Taxom |
| Amaurobiidae Thorell, 1870 | Amaurobiids | 6 | Species | Taxom |
| Amblyommidae Banks, 1907 | | 47 | Species | Taxom |
| Ameridae Grandjean, 1965 | | 2 | Species | Taxom |
| Amerobelbidae Grandjean, 1954 | | 1 | Species | Taxom |
| Ameroseiidae Evans, 1961 | | 4 | Species | Taxom |
| Ammotrechidae Roewer, 1934 | Curve-faced solifugid | 2 | Species | Taxom |
| Anapidae Simon, 1895 | Anapid spiders | 1 | Species | Taxom |
| Anisitsiellidae Koenike, 1910 | | 3 | Species | Taxom |
| Anyphaenidae Bertkau, 1878 | Anyphaenid sac spiders | 9 | Species | Taxom |
| Apheviderulicidae Gerecke, Smi..., 1999 | | 1 | Species | Taxom |
| Araneidae Simon, 1895 | Golden orb web spiders | 95 | Species | Taxom |
| Argasidae C. L. Koch, 1844 | Soft tick | 26 | Species | Taxom |
| Arrenuridae Thor, 1900 | | 5 | Species | Taxom |
| Ascidae Oudemans, 1905 | | 0 | Species | Taxom |
| Astegistidae Balogh, 1961 | | 1 | Species | Taxom |
| Atemnidae Chamberlin, 1931 | | 5 | Species | Taxom |
| Aturidae Thor, 1900 | | 2 | Species | Taxom |
| Atypidae Thorell, 1870 | Atypical tarantulas | 2 | Species | Taxom |
| Autognetidae Grandjean, 1960 | | 1 | Species | Taxom |
| Avenzoariidae Oudemans, 1905 | | 1 | Species | Taxom |
| Barychelidae Simon, 1889 | Brush-footed trapdoors | 2 | Species | Taxom |
| Basilobelbidae Balogh, 1961 | | 0 | Species | Taxom |
| Bdellidae Dugès, 1834 | Snout Mites | 1 | Species | Taxom |
| Belbidae (Willmann, 1931) | | 1 | Species | Taxom |
| Blattisociidae (Garman, 1948) | | 2 | Species | Taxom |
| Bothriuridae Simon, 1880 | | 4 | Species | Taxom |
| Brachychthoniidae Thor, 1934 | | 4 | Species | Taxom |
| Buthidae C. L. Koch, 1837 | Arrowbreasted scorpions | 119 | Species | Taxom |
| Caleremaeidae Grandjean, 1965 | | 1 | Species | Taxom |
| Caloppiidae (Balogh, 1960) | | 0 | Species | Taxom |
| Camisiidae Oudemans, 1900 | | 1 | Species | Taxom |
| Canestriniidae Berlese, 1884 | | 3 | Species | Taxom |
| Caponiidae Simon, 1890 | Caponiid spiders | 2 | Species | Taxom |
| Caraboctonidae Kraepelin, 1905 | | 1 | Species | Taxom |
| Carabodidae Koch, 1837 | | 15 | Species | Taxom |
| Carpoglyphidae Oudemans, 1923 | Driedfruit mites | 1 | Species | Taxom |
| Cepheusidae Berlese, 1896 | | 9 | Species | Taxom |
| Ceratoppiidae (Kunst, 1971) | | 2 | Species | Taxom |
| Ceratozetidae Jacot, 1925 | | 7 | Species | Taxom |
| Chactidae Reginald Inn..., 1893 | Fatclaw scorpions | 1 | Species | Taxom |
| Chaetodactylidae Zakhvatkin, 1941 | | 3 | Species | Taxom |
| Chamobatidae Thor, 1937 | | 4 | Species | Taxom |
| Charontidae Simon, 1892 | | 1 | Species | Taxom |
| Cheiracanthiidae Wagner, 1887 | Eutichurid Spiders | 1 | Species | Taxom |
| Cheiridiidae Hansen, 1893 | | 4 | Species | Taxom |
| Cheliferidae Risso, 1826 | | 40 | Species | Taxom |
| Chernetidae Menge, 1855 | | 18 | Species | Taxom |
| Cheyletidae Leach, 1815 | | 21 | Species | Taxom |
| Chirodiscidae Trouessart, 1892 | | 2 | Species | Taxom |
| Chortoglyphidae Berlese, 1897 | | 1 | Species | Taxom |
| Chthoniidae Daday, 1888 | | 53 | Species | Taxom |
| Cithaeronidae Simon, 1893 | Cithaeronid spiders | 2 | Species | Taxom |
| Clubionidae Wagner, 1887 | Clubiones | 26 | Species | Taxom |
| Corinnidae Karsch, 1880 | Ant-like Sac Spiders | 28 | Species | Taxom |
| Cosmetidae C. L. Koch, 1839 | | 5 | Species | Taxom |
| Cosmochthoniidae Grandjean, 1946 | | 2 | Species | Taxom |
| Crotoniidae Thorell, 1876 | | 5 | Species | Taxom |
| Ctenidae Keyserling, 1877 | Tropical wolf spiders | 2 | Species | Taxom |
| Ctenizidae Thorell, 1887 | Cork-lid trapdoor spider | 3 | Species | Taxom |
| Ctenobelbidae Grandjean, 1965 | | 1 | Species | Taxom |
| Cymbaeremaeidae Sellnick, 1928 | | 2 | Species | Taxom |
| Cyrtaucheniidae Simon, 1892 | Cyrtaucheiid spiders | 17 | Species | Taxom |
| Daesiidae Kraepelin, 1899 | | 23 | Species | Taxom |
| Damaeidae Berlese, 1896 | | 8 | Species | Taxom |
| Deinopidae C. L. Koch, 1850 | Net-casters | 1 | Species | Taxom |
| Demodecidae Nicolet, 1855 | Follicle mites | 2 | Species | Taxom |
| Dermationidae Fain, 1965 | | 0 | Species | Taxom |
| Dictynidae O. P-Cambridge, 1871 | Dictynid spiders | 77 | Species | Taxom |
| Dipluridae Simon, 1889 | Curtainweb Spiders | 2 | Species | Taxom |
| Diptilomiopidae Boczek, 1964 | | 3 | Species | Taxom |
| Drymobatidae J. & P. Balogh, 1984 | | 0 | Species | Taxom |
| Dysderidae C. L. Koch, 1837 | Dysderid spiders | 151 | Species | Taxom |
| Epidermoptidae Trouessart, 1892 | | 2 | Species | Taxom |
| Eremaeidae Oudemans, 1900 | | 2 | Species | Taxom |
| Eremobatidae Kraepelin, 1899 | | 3 | Species | Taxom |
| Eremobelbidae Balogh, 1961 | | 1 | Species | Taxom |
| Eresidae C. L. Koch, 1851 | Eresid spiders | 27 | Species | Taxom |
| Ereynetidae Schrank, 1776 | | 1 | Species | Taxom |
| Eriophyidae Nalepa, 1898 | Blister mites | 17 | Species | Taxom |
| Erythraeidae Oudemans, 1902 | | 10 | Species | Taxom |
| Eukoeneniidae Condé, 1965 | | 6 | Species | Taxom |
| Eupalopsellidae Willmann, 1952 | | 2 | Species | Taxom |
| Euphthiracaridae Jacot, 1930 | | 6 | Species | Taxom |
| Euscorpiidae Laurie, 1896 | Shorttail scorpions | 4 | Species | Taxom |
| Eustathiidae Oudemans, 1905 | | 2 | Species | Taxom |
| Eylaidae Leach, 1815 | | 4 | Species | Taxom |
| Fedrizziidae Trägårdh, 1937 | | 1 | Species | Taxom |
| Feltriidae Viets, 1926 | | 1 | Species | Taxom |
| Filistatidae Ausserer, 1867 | Crevice weaver | 18 | Species | Taxom |
| Galeodidae Sundevall, 1833 | | 37 | Species | Taxom |
| Galumnellidae Piffl, 1970 | | 0 | Species | Taxom |
| Galumnidae Jacot, 1925 | | 15 | Species | Taxom |
| Garypidae Simon, 1879 | | 5 | Species | Taxom |
| Garypinidae Daday, 1888 | | 6 | Species | Taxom |
| Gastronyssidae Fain, 1956 | | 2 | Species | Taxom |
| Geogarypidae Chamberlin, 1930 | | 4 | Species | Taxom |
| Glycyphagidae De Geer, 1778 | | 8 | Species | Taxom |
| Gnaphosidae Pocock, 1898 | Flat-bellied ground spiders | 266 | Species | Taxom |
| Gonyleptidae Sundevall, 1833 | | 5 | Species | Taxom |
| Gustaviidae Oudemans, 1900 | | 3 | Species | Taxom |
| Gymnobisiidae Beier, 1947 | | 2 | Species | Taxom |
| Gymnodamaeidae Grandjean, 1954 | | 2 | Species | Taxom |
| Hahniidae Bertkau, 1878 | Dwarf sheet spiders | 8 | Species | Taxom |
| Halacaridae Murray, 1877 | Sea mites | 7 | Species | Taxom |
| Haplochthoniidae Van der Hammen, 1959 | | 1 | Species | Taxom |
| Haplozetidae Grandjean, 1936 | | 7 | Species | Taxom |
| Hemileiidae (J. & P. Balogh, 1984) | | 3 | Species | Taxom |
| Hemisarcoptidae Oudemans, 1904 | | 1 | Species | Taxom |
| Hemiscorpiidae Pocock, 1893 | Longtail rock scorpions | 1 | Species | Taxom |
| Hermanniellidae Grandjean, 1934 | | 2 | Species | Taxom |
| Hermanniidae Sellnick, 1928 | | 4 | Species | Taxom |
| Hersiliidae Thorell, 1870 | Hersiliids | 10 | Species | Taxom |
| Heterozerconidae Berlese, 1892 | | 1 | Species | Taxom |
| Hexathelidae Simon, 1892 | Australian funnelweb spiders | 1 | Species | Taxom |
| Histiostomatidae Berlese, 1897 | | 2 | Species | Taxom |
| Hormuridae Laurie, 1896 | | 1 | Species | Taxom |
| Hubbardiidae Cook, 1899 | Hubbardiid shorttailed whipscorpions | 2 | Species | Taxom |
| Humerobatidae Grandjean, 1970 | | 2 | Species | Taxom |
| Hyadesiidae Halbert, 1915 | | 1 | Species | Taxom |
| Hydrachnidae Leach, 1815 | | 1 | Species | Taxom |
| Hydrovolziidae Thor, 1905 | | 1 | Species | Taxom |
| Hydryphantidae Piersig, 1896 | | 13 | Species | Taxom |
| Hygrobatidae Koch, 1842 | | 11 | Species | Taxom |
| Hypochthoniidae Berlese, 1910 | | 1 | Species | Taxom |
| Hypoderidae Murray, 1877 | | 1 | Species | Taxom |
| Ideoroncidae Chamberlin, 1930 | | 2 | Species | Taxom |
| Idiopidae Simon, 1892 | Armored trapdoor spiders | 2 | Species | Taxom |
| Ixodidae C. L. Koch, 1844 | Hard Tick | 26 | Species | Taxom |
| Johnstonianidae Thor, 1935 | | 2 | Species | Taxom |
| Karschiidae Walter, 1889 | | 8 | Species | Taxom |
| Kramerellidae Gaud & Mouchet, 1961 | | 1 | Species | Taxom |
| Laelapidae Berlese, 1892 | | 11 | Species | Taxom |
| Laminosioptidae Vitzthum, 1931 | | 3 | Species | Taxom |
| Lardoglyphidae Oudemans, 1927 | | 0 | Species | Taxom |
| Lebertiidae Thor, 1900 | | 3 | Species | Taxom |
| Leeuwenhoekiidae Womersley, 1944 | Chigger mites | 1 | Species | Taxom |
| Leptonetidae Simon, 1890 | Cave spiders | 3 | Species | Taxom |
| Liacaridae Sellnick, 1928 | | 6 | Species | Taxom |
| Licneremaeidae Grandjean, 1931 | | 1 | Species | Taxom |
| Licnobelbidae (Grandjean, 1965) | | 1 | Species | Taxom |
| Liebstadiidae J. & P. Balogh, 1984 | | 3 | Species | Taxom |
| Limnesiidae Thor, 1900 | | 5 | Species | Taxom |
| Linyphiidae Blackwall, 1859 | Dwarf spiders | 325 | Species | Taxom |
| Liocranidae Simon, 1897 | Liocranid sac spiders | 24 | Species | Taxom |
| Listrophoridae Mégnin & Tro..., 1884 | | 1 | Species | Taxom |
| Lohmanniidae Berlese, 1916 | | 4 | Species | Taxom |
| Lycosidae Lehtinen & H..., 1979 | Ground Spiders | 155 | Species | Taxom |
| Machuellidae Balogh, 1983 | | 1 | Species | Taxom |
| Macrochelidae Vitzthum, 1930 | | 4 | Species | Taxom |
| Macronyssidae Oudemans, 1936 | Macronyssid Mites | 5 | Species | Taxom |
| Malaconothridae Berlese, 1916 | | 0 | Species | Taxom |
| Melicharidae (Hirschmann, 1962) | | 1 | Species | Taxom |
| Mesoplophoridae Ewing, 1917 | | 1 | Species | Taxom |
| Micreremidae Grandjean, 1954 | | 1 | Species | Taxom |
| Microdispidae Cross, 1965 | | 2 | Species | Taxom |
| Microstigmatidae Raven & Plat..., 1981 | Microstigmatid spiders | 1 | Species | Taxom |
| Microtrombidiidae Womersley, 1936 | Micro velvet mites | 3 | Species | Taxom |
| Microzetidae Grandjean, 1936 | | 1 | Species | Taxom |
| Mideopsidae Koenike, 1910 | | 0 | Species | Taxom |
| Mimetidae Simon, 1881 | Pirate spider | 10 | Species | Taxom |
| Miturgidae Simon, 1885 | Long-legged sac spiders | 26 | Species | Taxom |
| Mochlozetidae Grandjean, 1960 | | 1 | Species | Taxom |
| Mummuciidae Mello-Leitão, 1938 | | 1 | Species | Taxom |
| Myobiidae Megnin, 1877 | | 4 | Species | Taxom |
| Myocoptidae Gunther, 1942 | | 1 | Species | Taxom |
| Mysmenidae Petrunkevitch, 1928 | Dwarf cobweb spiders | 6 | Species | Taxom |
| Nanhermanniidae Sellnick, 1928 | | 2 | Species | Taxom |
| Nemastomatidae Simon, 1872 | | 7 | Species | Taxom |
| Nemesiidae Simon, 1892 | Tube Trapdoor Spiders | 1 | Species | Taxom |
| Nenteriidae Hirschmann, 1979 | | 1 | Species | Taxom |
| Neobisiidae Chamberlin, 1930 | | 18 | Species | Taxom |
| Neoliodidae (Sellnick, 1928) | | 1 | Species | Taxom |
| Neopygmephoridae Cross, 1965 | | 1 | Species | Taxom |
| Nesticidae Simon, 1894 | Cave cobweb spider | 3 | Species | Taxom |
| Nosybelbidae Mahunka, 1994 | | 0 | Species | Taxom |
| Nothridae Berlese, 1896 | | 5 | Species | Taxom |
| Ochyroceratidae Fage, 1912 | Midget ground weaver | 1 | Species | Taxom |
| Oecobiidae Blackwall, 1862 | Disc web spider | 61 | Species | Taxom |
| Ologamasidae Ryke, 1962 | | 14 | Species | Taxom |
| Olpiidae Banks, 1895 | | 19 | Species | Taxom |
| Oonopidae Simon, 1890 | Dwarf Cell Spiders | 44 | Species | Taxom |
| Opilioacaridae With, 1902 | | 1 | Species | Taxom |
| Oppiidae Sellnick, 1937 | | 29 | Species | Taxom |
| Oribatellidae Jacot, 1925 | | 6 | Species | Taxom |
| Oribatulidae Thor, 1929 | | 11 | Species | Taxom |
| Oribellidae (Kunst, 1971) | | 2 | Species | Taxom |
| Oribotritiidae Grandjean, 1954 | | 2 | Species | Taxom |
| Oripodidae Jacot, 1925 | | 1 | Species | Taxom |
| Otopheidomenidae Treat, 1955 | | 1 | Species | Taxom |
| Oxyopidae Thorell, 1870 | Lynx spiders | 12 | Species | Taxom |
| Pachylaelapidae Berlese, 1913 | | 1 | Species | Taxom |
| Palpimanidae Thorell, 1870 | Palp-footed spiders | 6 | Species | Taxom |
| Papillonotidae Balogh, 1983 | | 0 | Species | Taxom |
| Parasitidae Oudemans, 1901 | Beetle Mites | 8 | Species | Taxom |
| Paratropididae Simon, 1889 | Bald-legged spiders | 0 | Species | Taxom |
| Parholaspididae Evans, 1956 | | 1 | Species | Taxom |
| Parhypochthoniidae Grandjean, 1932 | | 1 | Species | Taxom |
| Passalozetidae Grandjean, 1954 | | 2 | Species | Taxom |
| Phalangiidae Latreille, 1802 | Daddy-Long-Legs | 43 | Species | Taxom |
| Phalangodidae Simon, 1879 | | 3 | Species | Taxom |
| Phenopelopidae Petrunkevitch, 1955 | | 5 | Species | Taxom |
| Pheroliodidae Paschoal, 1987 | | 1 | Species | Taxom |
| Philodromidae Thorell, 1870 | False crab spiders | 64 | Species | Taxom |
| Pholcidae C. L. Koch, 1851 | Carpenter spider | 97 | Species | Taxom |
| Phrynichidae Simon, 1892 | | 4 | Species | Taxom |
| Phrynidae Blanchard, 1852 | | 2 | Species | Taxom |
| Phthiracaridae Perty, 1841 | | 34 | Species | Taxom |
| Phytoseiidae Berlese, 1916 | Phytoseiid mites | 26 | Species | Taxom |
| Pionidae Thor, 1900 | | 3 | Species | Taxom |
| Pisauridae Simon, 1890 | Big wolf spider | 6 | Species | Taxom |
| Plateremaeidae Trägårdh, 1931 | | 0 | Species | Taxom |
| Plectreuridae Simon, 1893 | Plectreurid spider | 1 | Species | Taxom |
| Podapolipidae Husband, 1990 | | 1 | Species | Taxom |
| Polyaspididae Berlese, 1913 | | 2 | Species | Taxom |
| Pseudochiridiidae Chamberlin, 1923 | | 1 | Species | Taxom |
| Psorergatidae Womersley, 1941 | | 1 | Species | Taxom |
| Psoroptidae Hering, 1838 | Scab mites | 2 | Species | Taxom |
| Pterolichidae Trouessart, 1899 | | 0 | Species | Taxom |
| Pteronyssidae Oudemans, 1941 | | 2 | Species | Taxom |
| Pterygosomatidae Womersley, 1941 | | 2 | Species | Taxom |
| Punctoribatidae Thor, 1937 | | 2 | Species | Taxom |
| Pyemotidae Newport, 1850 | | 1 | Species | Taxom |
| Pyroglyphidae Cunliffe, 1958 | Dust mites | 4 | Species | Taxom |
| Quadroppiidae Balogh, 1983 | | 2 | Species | Taxom |
| Raphignathidae Kramer, 1877 | | 1 | Species | Taxom |
| Rhagodidae Pocock, 1897 | | 16 | Species | Taxom |
| Rhinonyssidae Trouessart, 1895 | | 1 | Species | Taxom |
| Rhodacaridae Oudemans, 1902 | | 1 | Species | Taxom |
| Ricinoididae Ewing, 1929 | Hooded tickspiders | 2 | Species | Taxom |
| Salticidae Blackwall, 1842 | Jumping Spider | 306 | Species | Taxom |
| Samoidae Sørensen, 1886 | | 2 | Species | Taxom |
| Sarcoptidae Megnin, 1877 | Itch mites | 3 | Species | Taxom |
| Scheloribatidae Jacot, 1935 | | 5 | Species | Taxom |
| Sclerosomatidae Simon, 1879 | Sclerosomatid Harvestmen | 20 | Species | Taxom |
| Scorpionidae Pierre André..., 1802 | Largeclaw scorpions | 17 | Species | Taxom |
| Scutacaridae Paoli, 1911 | | 4 | Species | Taxom |
| Scutoverticidae Grandjean, 1954 | | 3 | Species | Taxom |
| Scytodidae Blackwall, 1864 | Glue spitter | 13 | Species | Taxom |
| Segestriidae Simon, 1893 | Six-eyed Spiders | 9 | Species | Taxom |
| Seiodidae Kethley, 1977 | | 1 | Species | Taxom |
| Selenopidae Simon, 1897 | Flatties | 5 | Species | Taxom |
| Senoculidae Simon, 1890 | Senoculid spiders | 1 | Species | Taxom |
| Sicariidae Keyserling, 1880 | Brown recluse spiders | 15 | Species | Taxom |
| Solpugidae Leach, 1815 | | 30 | Species | Taxom |
| Sparassidae Bertkau, 1872 | Giant crab spiders | 45 | Species | Taxom |
| Sperchontidae Thor, 1900 | | 4 | Species | Taxom |
| Sphaerochthoniidae Grandjean, 1947 | | 1 | Species | Taxom |
| Spinturnicidae Oudemans, 1902 | | 1 | Species | Taxom |
| Steganacaridae (Niedbała, 1986) | | 2 | Species | Taxom |
| Sternophoridae J.C. Chamberlin, 1923 | | 1 | Species | Taxom |
| Stigmaeidae Wood, 1967 | | 1 | Species | Taxom |
| Suctobelbidae Jacot, 1938 | | 12 | Species | Taxom |
| Suidasiidae Hughes, 1948 | | 0 | Species | Taxom |
| Syarinidae Chamberlin, 1930 | | 10 | Species | Taxom |
| Synaphridae Wunderlich, 1986 | Midget Spiders | 5 | Species | Taxom |
| Syringophilidae Lavoipierre, 1953 | Quill mites | 8 | Species | Taxom |
| Tanaupodidae Thor, 1935 | | 1 | Species | Taxom |
| Tarsonemidae Kramer, 1877 | Tarsonemid mites | 7 | Species | Taxom |
| Tectocepheidae Grandjean, 1954 | | 3 | Species | Taxom |
| Tegoribatidae Grandjean, 1954 | | 0 | Species | Taxom |
| Telemidae Fage, 1913 | Long-legged cave spider | 1 | Species | Taxom |
| Tengellidae (Dahl, 1908) | Tengellid spiders | 1 | Species | Taxom |
| Tenuipalpidae Berlese, 1913 | False spider mites | 6 | Species | Taxom |
| Teratothyadidae Viets, 1929 | | 0 | Species | Taxom |
| Tetrablemmidae O. P-Cambridge, 1873 | Armored spider | 1 | Species | Taxom |
| Tetragnathidae Menge, 1866 | Elongated Orb Weavers | 44 | Species | Taxom |
| Tetranychidae Donnadieu, 1875 | Spider mites | 62 | Species | Taxom |
| Thelyphonidae Lucas, 1835 | | 2 | Species | Taxom |
| Theraphosidae Thorell, 1870 | Bird-eating spiders | 16 | Species | Taxom |
| Theridiidae Sundevall, 1833 | Cobweb And Widow Spiders | 205 | Species | Taxom |
| Theridiosomatidae Simon, 1881 | Ray orbweavers | 3 | Species | Taxom |
| Thomisidae Sundevall, 1833 | Crab Spider | 89 | Species | Taxom |
| Titanoecidae Lehtinen, 1967 | Rock Weavers | 2 | Species | Taxom |
| Torrenticolidae Thor, 1902 | Torrent Mites | 15 | Species | Taxom |
| Trachelidae Simon, 1897 | | 3 | Species | Taxom |
| Trematuridae Berlese, 1917 | | 5 | Species | Taxom |
| Trochanteriidae Karsch, 1879 | Flat spiders | 8 | Species | Taxom |
| Trogulidae Sundevall, 1833 | | 7 | Species | Taxom |
| Trombellidae Thor, 1935 | | 1 | Species | Taxom |
| Trombiculidae Ewing, 1929 | Chigger mites | 5 | Species | Taxom |
| Trombidiidae Leach, 1815 | Beer Bahuti | 13 | Species | Taxom |
| Trouessartiidae Gaud, 1957 | | 1 | Species | Taxom |
| Tydeidae Kramer, 1877 | Tydeid mites | 7 | Species | Taxom |
| Uloboridae Thorell, 1869 | Cribellate orb weavers | 11 | Species | Taxom |
| Unionicolidae Oudemans, 1909 | | 3 | Species | Taxom |
| Urodinychidae Berlese, 1917 | | 1 | Species | Taxom |
| Uropodidae Kramer, 1881 | | 4 | Species | Taxom |
| Vaejovidae Thorell, 1876 | | 3 | Species | Taxom |
| Varroidae Delfinado & ..., 1974 | | 1 | Species | Taxom |
| Winterschmidtiidae Oudemans, 1923 | | 0 | Species | Taxom |
| Withiidae Chamberlin, 1931 | | 7 | Species | Taxom |
| Xenillidae Woolley & Hi..., 1966 | | 8 | Species | Taxom |
| Zalmoxidae (Sörensen, 1886) | | 1 | Species | Taxom |
| Zerconidae Berlese, 1892 | | 4 | Species | Taxom |
| Zetorchestidae Michael, 1898 | | 1 | Species | Taxom |
| Zodariidae Thorell, 1881 | Ant spiders | 60 | Species | Taxom |
| Zoridae F. O. P-Camb..., 1893 | Wandering Spiders | 1 | Species | Taxom |
| Zoropsidae Bertkau, 1882 | False Huntsman Spiders | 6 | Species | Taxom |