A key and distribution map for all taxa of Eucalyptus ser. Orbifoliae Brooker & Hopper are provided. Eucalyptus minniritchi Nicolle is described to accommodate populations of mallees in central Australia previously referred to as E. orbifolia F. Muell. or E. websteriana Maiden and related to both. The new species differs from E. orbifolia in the smaller buds with a short hemispherical operculum, the smaller and narrower adult leaves and the generally smaller, hemispherical fruits and differs from E. websteriana in the consistently and strongly pruinose adult parts and generally coarser leaves, peduncles, pedicels, buds and fruits. E. lata L.A.S. Johnson & K.D. Hill, a species recently described to accommodate what is here recognized to be typical E. orbifolia, is synonymised with that earlier named species. The status of E. educta L.A.S. Johnson & K.D. Hill and its relationship to E. orbifolia is discussed.