Mayachernes maatiatus, a new genus and species of pseudoscorpion of the family Chernetidae (Arachnida: Pseudoscorpionida), is described from the Miocene Chiapas – Amber Lagerstätte, south of Mexico. This new fossil species represents an adult male specimen with hard–soft tissues preserved in great detail. It differs from all other living chernetids by a combination of diagnostic characters. Anatomical data were collected using high-resolution microscopy with regular to infrared-reflected light. Mayachernes maatiatus is the first newly described fossil species of pseudoscorpion from the Chiapas amber. This taxon also adds to knowledge of the Chernetidae diversity in the southernmost part of North America at the Neogene.