Fuel cell system and fuel cell vehicle

Disclosed are a fuel cell system and a fuel cell vehicle which suppress the occurrence of failure to fill hydrogen due to a determination that there is an abnormality when undesirable conditions suchas leaks of a hydrogen tank do not occur. In the fuel cell system, when filling hydrogen into a hydrogen tank is determined to be started, a transmitter configured to transmit a signal indicating pressure in the hydrogen tank to a hydrogen filling device transmits a first signal indicating that the pressure in the hydrogen tank is a first sensor value when the first sensor value detected by a first pressure sensor configured to detect pressure in a filling flow path connecting a filler port and the hydrogen tank is equal to or higher than a reference pressure predetermined to exceed the atmospheric pressure. Moreover, when the first sensor value is lower than the reference pressure, the transmitter transmits a second signal indicating that the pressure in the hydrogen tank is a second sensor value detected by a se