The present technology relates to a transmission apparatus, a transmission method, a reception apparatus, and a reception method that enable channel selection information and time information to be transmitted effectively.A transmission apparatus acquires channel selection information for selecting a service and time information used for synchronizations on a transmission side and a reception side, generates, as a physical layer frame constituted of a preamble and a data portion, the physical layer frame in which specific information including at least one of the channel selection information and the time information is arranged at a head of the data portion right after the preamble, and transmits the physical layer frame as digital broadcast signals. The present technology is applicable to IP packet broadcasting, for example.