A systematic and unified optimal inverter dispatch (OID) framework is proposed in this paper, with the goal of facilitating high PV penetration in existing distribution networks. The OID task involves solving an optimal power flow (OPF) problem to determine PV inverter active- and reactive-power set points, so that the network operation is optimized according to well-defined criteria (e.g., minimizing power losses), while ensuring voltage regulation and adhering to other electrical network constraints. The proposed OID framework provides increased flexibility over RPC or APC alone, by invoking a joint optimization of active and reactive powers. Indeed, although [4], [8]–[10], [12], and [13] (and pertinent references therein) demonstrated the virtues of RPC and APC in effecting voltage regulation, these strategies are based on local information and, therefore, they may not offer system-level optimality guarantees. On the other hand, by promoting network-level optimization, the OPF-based formulation proposed in this work inherently ensures systemlevel benefits