A system for thermionic energy generation, preferably including one or more thermionic energy converters, and optionally including one or more power inputs, airflow modules, and/or electrical loads. A thermionic energy converter, preferably including an emitter module, a collector module, and/or a seal, and optionally including a spacer. The thermionic energy converter preferably defines a chamber and/or a heating cavity. A method for thermionic energy generation, preferably including receiving power, emitting electrons, and/or receiving the emitted electrons, and optionally including convectively transferring heat.