The cytosol-facing organelle outer membrane (OM) is a layer that separates from but also communicates with cellular compartments for the import and exchange of proteins, metabolites and signaling molecules. OM resident proteins are also the targets of cellular surveillance systems by which the cell controls organelle homeostasis for promoting cell survival under stress. However, discovery of OM proteins and their dynamically interacting partners by traditional approaches can be very challenging. In this study, we developed an outer membrane proximity labeling system (OMPL) using biotin ligase mediated proximity biotinylation to map the proximity proteome of the cytosol-facing mitochondria, chloroplast and peroxisome outer membranes in living Arabidopsis cells. The power of this optimized system is highlighted by the discovery of the cytosolic factors and OM receptor candidates that are potentially involved in protein local translation and translocation, membrane contact sites and organelle quality control. Moreover, this OMPL plants generated in this study can be used for rapid and specific isolation of intact mitochondria and peroxisome. Our findings provide ample ground for further investigations on important questions in organelle biology.