Extracellular vesicles, including exosomes, and exomere nanoparticles, are under intense investigation for cargo that may serve as clinical biomarkers or therapeutic targets. Here, we report discovery of a new extracellular nanoparticle, termed supermeres. We performed LC/MS-MS proteomics analyses on gradient-purified sEVs, NVs, exomeres and supermeres. The proteomic profile of supermeres is clearly distinct from that of sEVs, NVs and exomeres. This study identifies a new functional nanoparticle replete with potential circulating biomarkers and therapeutic targets that can be exploited for clinical benefit in a host of diseases.