Abstract: To provide a sensor unit that can be easily attached to and detached from a seat in which a seated occupant is seated, and a seat equipped with a sensor unit. A sensor unit includes a sensor module including a biological sensor that detects a biological signal of a seated occupant, and a wireless communication unit that is connected to the biological sensor to wirelessly transmit the detected biological signal to an outside; and a sensor holder that holds the sensor module. The sensor holder includes a seat attachment portion detachably attached to an attached portion that is provided in a front surface of a seat cushion at a position at which the seated occupant is abuttable against the attached portion.