The present technology relates to a transmitting device, a transmitting method, a receiving device, and a receiving method, which are capable of improving immediacy and flexibility of an alert.A transmitting device generates transmission data in which an index associated with predetermined process-related information in a relevant table in which process-related information related to an output process of outputting an alert on a receiving side is registered in association with an index is included in data of a physical layer, the relevant table being included in data of a higher layer higher than the physical layer and supplied, and transmits the transmission data. The receiving device obtains a relevant table, receives transmission data, and acquires an index included in data of a physical layer from the transmission data. Then, the receiving device executes an output process corresponding to process-related information associated with the index included in the data of the physical layer in the relevant table. For example, the present technology can be applied in a case where an emergency alert is provided in television broadcasting.