A vehicular circuit body includes a trunk line that includes a power source line and a communication line, and that is routed in a vehicle body; and a plurality of control boxes that are disposed in a distribution manner along the trunk line. The trunk line includes a first trunk line portion extending in a front-and-rear direction of the vehicle body and a second trunk line portion extending in a leftward-and-rightward direction of the vehicle body. The plurality of control boxes include a branch control box that connects the first trunk line portion and the second trunk line portion, and distributes power from one of the first trunk line portion and the second trunk line portion to the other one.