Methods and apparatus for RFID communications in a process control system are disclosed. An example apparatus includes a radio-frequency identification tag operatively coupled to a field device of a process control system. The radio-frequency identification tag has a processor, an onboard memory, and an antenna. The onboard memory stores data received from the field device to be communicated to a radio frequency identification reader. Power for the processor and the onboard memory is to be drawn from control system power provided to the field device.