Bacteria of the genus Stenotrophomonas are found throughout the environment, in close association with soil, sewage, and plants. Stenotrophomonas maltophilia, the first member of this genus, is the predominant species, observed in soil, water, plants, animals, and humans. It is also an opportunistic pathogen associated with the increased number of infections in both humans and animals in recent years. In this article, we summarize all Stenotrophomonas species (mainly S. maltophilia) isolated from animals and food products of animal origin and further distinguish all isolates based on antimicrobial susceptibility and resistance phenotypes. The various mechanisms of both intrinsic and acquired antimicrobial resistance, which were mainly identified in S. maltophilia isolates of nosocomial infections, have been classified as follows: multidrug efflux pumps; resistance to β-lactams, aminoglycosides, quinolones, trimethoprim-sulfamethoxazole, and phenicols; and alteration of lipopolysaccharide and two-component regulatory systems. The dissemination, coselection, and persistence of resistance determinants among S. maltophilia isolates have also been elaborated.