To supply hot fuel to fuel injection valves by heating fuel in fuel heating devices to a higher temperature.

In this fuel supply device 1 for an internal combustion engine E, a fuel pump 6 for force-feeding the fuel stored in a fuel tank 2 to the fuel injection valve 4 side is installed in a fuel supply passage 5 for connecting the fuel tank 2 and the fuel injection valves 4, a first pressure regulating mechanism 7 for recirculating excess fuel to the upstream side when the fuel pressure on the downstream side is equal to or higher than a first predetermined value P1 is provided to the fuel supply passage 5 further on the downstream side than the fuel pump 6, the fuel heating devices 14 for heating the fuel are provided to the fuel supply passage 5 further on the downstream side than the first pressure regulating mechanism 7, and a second pressure regulating mechanism 10 for recirculating the excess fuel to the upstream side when the fuel pressure on the downstream side is equal to or higher than a second predetermined value P2 which is higher than the first predetermined value P1 is provided to the fuel supply passage 5 between the first pressure regulating mechanism 7 and the fuel heating devices 14. Consequently, the fuel pressures in the fuel heating devices 14 are increased so that the fuel can be heated to a higher temperature.