A female terminal fitting includes a bottom plate which extends in a front-back direction, a female electrical contact portion formed on a front side of the bottom plate, a board connecting portion extending backward of the bottom plate, and a stress relaxation portion. The bottom plate has a first stress relaxation portion which is resiliently deformable in an up-down direction. A side wall is erected from and formed on at least one side portion of the bottom plate in a right-left direction. A connecting portion connects to the board connecting portion in a state that the board connecting portion is arranged so as to be parallel to the front-back direction and is located more inside than the side wall. The connecting portion is a second stress relaxation portion which is resiliently deformable in the right-left direction and in the front-back direction.