A heat dissipation device is used in a circuit board, where the circuit board includes a chip and at least one positioning hole disposed around the chip, and each of the positioning holes has a bare metal area on its periphery. The heat dissipation device includes a heat dissipation element, a conductive element and at least one fixing part. The heat dissipation element is disposed on the chip; the conductive element is connected electrically to the bare metal area of the circuit board and the heat dissipation element respectively; the fixing part passes through the fixing holes and is connected to the positioning hole, so as to fix the heat dissipation element to the circuit board. A circuit board is also provided, which includes a substrate, a chip, a positioning hole and the heat dissipation device.