A resin-made fuel tank includes: a resin-made fuel tank main body provided by joining an upper half and a lower half; a barrier sheet layer that is provided on an inner surface of the fuel tank main body and that reduces permeation of a fuel from the fuel tank main body; and a front mounting stay and rear mounting stays for mounting the fuel tank main body to a vehicle body. The front mounting stay and the rear mounting stays are provided on the fuel tank main body at positions vertically spaced from an upper joint surface and a lower joint surface at which the upper half and the lower half re joined to each other.