Here, we illustrate the proteomic composition and hydrolytic capacity of outer membrane vesicles (OMVs) produced by F. succinogenes during growth on Avicel cellulose and show that the OMVs are equipped with a highly versatile polysaccharide-degrading machinery. Proteomic assessment identified an enrichment of acidic proteins as well as carbohydrate-active enzymes of varying putative functions. Further, we show that the OMVs contain a membrane-bound multiprotein complex containing four proteins.