The present technology relates to a communication apparatus and a communication system achieving efficient utilization of a transfer path of a wireless LAN. A communication apparatus according to an aspect of the present technology transmits a first trigger frame containing a transmission parameter used for data transmission to a plurality of apparatuses belonging to a wireless LAN, and receives data multiplexed and transmitted from the plurality of apparatuses having received the first trigger frame in accordance with the transmission parameter. In addition, the communication apparatus receives a second trigger frame transmitted from a predetermined apparatus of the plurality of apparatuses, and transmits multiplexed data to the predetermined apparatus in accordance with a transmission parameter contained in the received second trigger frame. The present technology is applicable to a communication apparatus in a wireless LAN.