Twenty-four fossil gall midges (Cecidomyiidae) described from 1917–2020 from Mesozoic deposits, mostly ambers, are reviewed. Information from the original publications is used as the basis for reinterpretation, when such is regarded as appropriate here. As a result, the fossil record of cecidomyiids from the Mesozoic comprises representatives of the following subfamilies and tribes, all mycophagous (numbers in parentheses refer to species described): Catotrichinae (1); Micromyinae: Catochini (2), Amediini (1), Campylomyzini (1), Micromyini (2) and Aprionini (1); Winnertziinae: Heteropezini (2), Diallactiini (4) and Winnertziini (1); Porricondylinae: Dicerurini (1). Other Winnertziinae (3) and Micromyinae (5) cannot be classified to tribe because information on critical morphological structures is unavailable; they are thus considered incertae sedis. Members of the Lestremiinae sensu stricto are unrecorded from the Mesozoic, as are any Cecidomyiinae (the only subfamily containing phytophages and predators). Commonly occurring reasons for misinterpretation of amber fossils are the non-recognition of artefacts and the unfamiliarity with group-specific literature regarding prevailing taxonomic concepts and the morphological diversity found in Cecidomyiidae. These causes as well as obvious differences between neontological and paleontological taxonomic practices are discussed. Amediini trib. nov. Jaschhof, 2021 is introduced as a new tribe of the Micromyinae, to absorb the genera Amedia Jaschhof, 1997 (extant, North America, type genus), Amediella Jaschhof, 2003 (extant, New Zealand) and Eltxo Arillo & Nel, 2000 (extinct, Alava amber). A diagnosis of the new tribe is given. Krassiloviolini Fedotova & Perkovsky, 2017 is a new junior synonym of Heteropezini Schiner, 1868. Amediini Plakidas, 2017 and Zarqacecidomyius singularis Kaddumi, 2007 are nomina nuda.
New gall midges (Diptera, Cecidomyiidae) associated with Eugenia uniflora and Psidium cattleianum (Myrtaceae)