No effective disease-modifying osteoarthritis (OA) drugs are available; therefore, regenerative therapies including mesenchymal stromal cells (MSCs) are commonly employed. Recently, MSC-derived extracellular vesicles (EVs) have been investigated as potential cell-free orthobiologics. EVs are cell-derived particles that can contain diverse cargos, from proteins to miRNAs to whole organelles, including mitochondria (termed mitovesicles; mtEVs). The objectives of this study were to: determine if MSC-derived EVs contain mitochondria; characterize mtEV size and mitochondrial-cargos; and determine if plasma is a source of mtEVs. EVs were isolated from equine MSC (eMSC)-conditioned media, stained with Calcein and Mitotracker, then analyzed by flow cytometry. Mitovesicles were identified as double-positive fluorescent events. Immunoblotting was performed on equine plasma-derived EVs by incubating with antibodies to detect cellular (Iκβα) and mitochondria-specific markers (COX IV, VDAC, ATP5A1). Results indicated 72% of all EVs were mtEVs. Mitovesicles varied in size, with ∼ 50% greater than 500 nm. Of the largest EVs, nearly all (99%) contained intact mitochondria. Immunoblot confirmed mitochondrial cargos. Our group has shown that mitochondrial dysfunction is an early response of chrondrocytes to injury, and that MSCs can transfer healthy mitochondria to dysfunctional cells as a potential repair mechanism. While this study confirms the presence of mtEVs in eMSC cultures and equine plasma, studies investigating the functional potential of mtEVs are ongoing. Our findings that eMSCs and plasma are sources of distinct mtEV subpopulations suggest an opportunity to develop novel cell-free orthobiologics to improve cartilage healing after injury.