A wire harness includes at least two electrical wires, and a connection unit via which each of the at least two electrical wires are connected. The connection unit includes a circuit board connected to the at least two electrical wires, and a conductor member extending downward from the circuit board, the conductor member being electrically connected to a ground pattern on the circuit board. The connection unit is attached to a vehicle body in a state where the conductor member is in contact with a grounding conductor formed on the vehicle body when the connection unit is disposed on the vehicle body. Therefore, the circuit board can be directly connected to the ground via the conductor member only by disposing the connection unit on the vehicle body.