A fuel pump includes: an outer gear having a plurality of inner teeth; an inner gear having a plurality of outer teeth and eccentrically meshing with the outer gear; and a pump housing that defines a cylindrical gear housing chamber housing the outer gear and the inner gear to be rotatable. The outer gear and the inner gear rotate, while expanding and contracting a volume of a plurality of pump chambers formed between the outer gear and the inner gear, to sequentially draw fuel into and discharge from the pump chamber. An inner circumference part of the pump housing has a radially-inside corner part opposing a radially-outside corner part of an outer circumference part of the outer gear, and the pump housing has an annular groove formed in an annular shape all around the radially-inside corner part.