There is provided a mower in which a guide member does not easily protrude on the side of the mower, and a grass mowing machine including the same. A mower for discharging mowed grasses from a discharge port provided in a side part of a mower deck to an exterior of the mower deck includes a flexible rubber sheet formed in a flat plate shape, a pivot frame, support frames, and a pivot shaft for attaching the rubber sheet to the mower deck oscillatably in the up and down direction, and fixing members for fixing the rubber sheet to the mower deck in a state that the rubber sheet is bent into a shape capable of guiding the mowed grasses discharged from the discharge port.
