The exotic Brazilian peppertree, Schinus terebinthifolius Raddi, is an invasive plant that readily displaces native vegetation and develops monospecific stands in central and south Florida’s native ecosystems. Despite prior arthropod surveys of S. terebinthifolius in its adventive range, little is known concerning the acarofauna associated with the weed in Florida. Leaves of S. terebinthifolius also vary in the presence and development of domatia, which are small morphological structures that may benefit mites. We assessed the development of new mite associations with S. terebinthifolius in Florida and quantified within-plant distribution of these arthropods. Mites inhabited over one-third of the sampled leaves with greatest species diversity in the Prostigmata, followed by Mesostigmata, Astigmata, and Cryptostigmata, respectively. Fungivorous mites (dominated by Lorryia formosa) were the most common feeding guild, predatory mites were the most diverse, and herbivorous mites were rarely encountered during the survey. Interior leaves supported greater populations of mites than exterior leaves, whereas height of leaves in the canopy did not affect mite distributions. Foliar domatia varied in development and occurred on nearly two-thirds of the leaves sampled. More than three-quarters of all mites collected were found on domatia-bearing leaves, which supported three times more mites per leaf than leaves without domatia. Mite densities increased concomitantly with the number of domatia, while domatia development only affected tydeids and number of leaves had no effect. The potential influence of domatia-mediated, tritrophic interactions among existing predators and a potential biological control agent of S. terebinthifolius are discussed.