Trichomonads are ubiquitous anaerobic flagellated protists belonging to phylum Parabasalia. They infect many vertebrate and invertebrate species, with four species being classically recognized as human parasites: Trichomonas vaginalis, which causes the most common non-viral sexually transmitted infection; Trichomonas tenax, which is associated with periodontal disease; and Dientamoeba fragilis and Pentatrichomonas hominis, which are associated with intestinal upsets and may have a zoonotic origin. We are investigating the genomes of this “understudied, undervalued, but amazingly interesting” microbial eukaryotic lineage. The first trichomonad genome sequencing project was devoted to T. vaginalis (Carlton et al., Science 2007), and we have leveraged this data trove in several ways. One standout finding of the project was the massive infiltration of the T. vaginalis genome by transposable elements (TEs). In this talk we will describe effects of these genomic “space invaders” on expression of the host protist’s genes, as well as the regulation of TE genes themselves by small RNA molecules. We have also generated partial genome sequence data for ~100 T. vaginalis isolates to identify potential new biomarkers of antiparasite drug resistance, which has become a problem for treatment of trichomoniasis. Finally, we have developed 18S rRNA amplicon sequencing methods to survey T. vaginalis and other trichomonads in the urban environment of New York City.