• Quercus Linnaeus, 1753
• Quercus aaata C.H. Mull.
• Quercus abbreviata Vuk. accepted as Quercus robur Linnaeus
• Quercus abelicea Lam.
• Quercus abendanonii Valeton accepted as Lithocarpus havilandii (Stapf) Barnett
• Quercus abietum Kotschy ex A. DC. accepted as Quercus petraea (Matt.) Liebl.
• Quercus acapulcensis Trel. accepted as Quercus salicifolia Née
• Quercus acatenangensis Trel. accepted as Quercus laurina Bonpl.
• Quercus accessiva Gand. accepted as Quercus robur Linnaeus
• Quercus accomodata Gand. accepted as Quercus robur Linnaeus
• Quercus acerifolia (E.J. Palmer) Stoynoff & Hess
• Quercus acerifolia Petz. & G. Kirchn. accepted as Quercus rubra Linnaeus
• Quercus acherdophylla Trel.
• Quercus achoteana Trel. accepted as Quercus segoviensis Liebm.
• Quercus acrodonta Seemen
• Quercus acroglandis Kellogg accepted as Quercus agrifolia Née
• Quercus aculcingensis Trel.
• Quercus acuminata (Michx.) Sarg. accepted as Quercus muehlenbergii Engelm.
• Quercus acuminata Endl. accepted as Lithocarpus korthalsii (Endl.) Soepadmo
• Quercus acuminata M. Martens & Galeotti accepted as Quercus candicans Née
• Quercus acuminata Roxb. accepted as Lithocarpus acuminatus (Roxb.) Rehder
• Quercus acuminatissima (Blume) A. DC. accepted as Castanopsis acuminatissima (Blume) A. DC.
• Quercus acuminatissima Merr. accepted as Lithocarpus mindanaensis (Elmer) Rehder
• Quercus acuta Buch.-Ham. ex Wall. accepted as Castanopsis tribuloides (Sm.) A. DC.
• Quercus acuta Raf. accepted as Quercus coccinea Münchh.
• Quercus acuta Siebold ex Blume accepted as Lithocarpus glaber (Thunb.) Nakai
• Quercus acuta Thunb.
• Quercus acutangula Trel.
• Quercus acutidens Torr.
• Quercus acutidentata (Maxim.) Koidz. (unaccepted)
• Quercus acutifolia Née
• Quercus acutiglandis Sarg. accepted as Quercus agrifolia Née
• Quercus acutiloba Borbás accepted as Quercus robur Linnaeus
• Quercus acutissima Carruth.
• Quercus adjecta Gand. accepted as Quercus pubescens Willd.
• Quercus admixta Gand. accepted as Quercus pubescens Willd.
• Quercus adriatica Gand. accepted as Quercus petraea (Matt.) Liebl.
• Quercus adriatica Simonk.
• Quercus aegilopifolia Boiss. ex Endl. accepted as Quercus lusitanica Lam.
• Quercus aegilops Griseb. accepted as Quercus trojana Webb
• Quercus aegilops Linnaeus accepted as Quercus ithaburensis Decne.
• Quercus aegilops Mill. accepted as Quercus pubescens Willd.
• Quercus aegilops Scop. accepted as Quercus cerris Linnaeus
• Quercus aegylopifolia Boiss. ex A. DC. accepted as Quercus lusitanica Lam.
• Quercus aegylopifolia Pers. accepted as Quercus hispanica Lam.
• Quercus aequivenulosa Trel. accepted as Quercus coffeicolor Trel.
• Quercus aerea Trel.
• Quercus aesculus Boiss. accepted as Quercus robur Linnaeus
• Quercus aestivalis Steven accepted as Quercus robur Linnaeus
• Quercus afares Pomel
• Quercus affinis M. Martens & Galeotti accepted as Quercus martensiana Trel.
• Quercus affinis Scheidw.
• Quercus afghanistanensis K. Koch accepted as Quercus robur Linnaeus
• Quercus africana Barrow
• Quercus agbayi Lavallée
• Quercus agnostifolia K. Koch accepted as Quercus nigra Linnaeus
• Quercus agrifolia Batt. & Trab. accepted as Quercus auzandrii Gren. & Godr.
• Quercus agrifolia Née
• Quercus agriobalanidea Papaioann.
• Quercus aguana Trel. accepted as Quercus purulhana Trel.
• Quercus airensis Franco & Vasc. accepted as Quercus auzandrii Gren. & Godr.
• Quercus aitchisoniana A. Camus accepted as Quercus castaneifolia C.A. Mey.
• Quercus aizoon Koehne accepted as Quercus hispanica Lam.
• Quercus ajoensis C.H. Mull.
• Quercus ajudaghiensis Steven ex Petzh. & G. Kirchn. accepted as Quercus hartwissiana Steven
• Quercus alamarensis C.H. Mull.
• Quercus alamo Benth. accepted as Quercus candicans Née
• Quercus alamosensis Trel. accepted as Quercus castanea Née
• Quercus alba Linnaeus
• Quercus albescens Rouy ex A. Camus
• Quercus albicaulis Chun & W.C. Ko
• Quercus albifolia C.H. Mull.
• Quercus albocincta Trel.
• Quercus alexanderi Britton accepted as Quercus muehlenbergii Engelm.
• Quercus aliena Blume
• Quercus aliena J.-G. Jack
• Quercus alienocrispula H. Ohba accepted as Quercus pongtungensis Uyeki
• Quercus alienoides Uyeki
• Quercus alienoserratoides T.B. Lee
• Quercus allardii Hy accepted as Quercus rosacea Bechst.
• Quercus alligata Gand. accepted as Quercus robur Linnaeus
• Quercus allorgeana A. Camus
• Quercus almaguerensis Bonpl. accepted as Quercus humboldtii Bonpl.
• Quercus alnifolia Poech
• Quercus alnoides Lavallée
• Quercus alpescens Trel.
• Quercus alpestris Boiss. accepted as Quercus faginea Lam.
• Quercus alpina Endl. accepted as Quercus ilex Linnaeus
• Quercus altissima Petz. & G. Kirchn. accepted as Quercus robur Linnaeus
• Quercus alvarezensis Trel. accepted as Quercus rugosa Née
• Quercus alveolata Trel. accepted as Quercus deserticola Trel.
• Quercus alvordiana Eastw.
• Quercus amamiana Hatus. accepted as Quercus glauca Thunb.
• Quercus ambigens Jord.
• Quercus ambigua Bonpl. accepted as Quercus rugosa Née
• Quercus ambigua F. Michx. accepted as Quercus rubra Linnaeus
• Quercus ambigua Kit. ex Rochel accepted as Quercus pubescens Willd.
• Quercus ambivenulosa Trel. accepted as Quercus laurina Bonpl.
• Quercus amblyodes Gand. accepted as Quercus pubescens Willd.
• Quercus amblyoprion Woronow ex Maleev accepted as Quercus infectoria G. Olivier