Three species of fossil smaridid mites (Parasitengona, Smarididae) are described based on postlarval forms. Fessonia wunderlichi sp. nov., Fessonia grabenhorsti sp. nov. and Fessonia groehni sp. nov. were discovered in Eocene (ca. 44–50 Ma) Baltic amber and the former two also in the probably younger Oligocene (ca. 23–25 Ma) Bitterfeld amber. Although Smarididae has been reported from Baltic (and other) Cenozoic amber localities, these are the first species from this group to be formally described. Fessonia wunderlichi sp. nov. and Fessonia grabenhorsti sp. nov. are also the first named mites from Bitterfeld amber, and at the same time the first examples of mite species common to both the Baltic and Bitterfeld deposits. Fessonia groehni sp. nov. is known from a single specimen originating from the Baltic deposit. Although the thickened hindlimbs seen in Fessonia wunderlichi sp. nov. resemble the modern smaridid genus Kraussiana Southcott, 1961, the structure of the crista metopica implies another extant genus — Fessonia von Heyden, 1826 — which we redefine here to accommodate the morphology of the amber species. An outline of previous findings of terrestrial Parasitengona in amber is also provided.