A control unit arrangement structure for a saddle riding-type vehicle includes a control unit (30) mounted in a saddle riding-type vehicle (1), and a plurality of connectors (40) connected to the control unit (30), wherein the control unit (30) includes a plurality of joining parts (34) which transmit electric signals, the plurality of joining parts (34) are respectively connected to the plurality of connectors (40), an outer periphery of the control unit (30) is disposed inward from an outer peripheries of the connectors (40) when seen in a connection direction (Vc) between the joining parts (34) and the connectors (40), and a single support member (50) which supports the plurality of connectors (40) is provided.