Two Fergusonina (Diptera: Fergusoninidae) flies are described from terminal leaf bud galls on high-elevation snow gums (Eucalyptus pauciflora complex) in the Australian Alps. The new species, Fergusonina daviesae Nelson and Yeates sp. nov. and Fergusonina taylori Nelson and Yeates sp. nov., occur in sympatry at the six collection locations. After extensive field studies, these are the only two Fergusonina species that have been found on high-elevation snow gums. The two can be distinguished from each other by differences in adult size and markings on the mesonotum. The mature larvae, which are superficially similar to each other, but differ in shape and details of the dorsal shield ornamentation, are described. Additionally, a cytochrome oxidase I (COI) sequence divergence of 12.55% between the two putative species supports the conclusions drawn from the morphological study. The two species can be distinguished from other described species of Fergusonina by host specificity, adult colour, setation and larval dorsal shield morphology.