Vehicle body structure of cab-over type vehicle

A vehicle body structure of a cab-over type vehicle includes: a floor cross member extending in a vehicle width direction along a lower surface of a floor panel of a cab body and including a pair of mount portions to which mounts are attached on both sides in the vehicle width direction; and a gusset extending in a vehicle front-rear direction between the pair of mount portions below the floor panel, including one end portion joined to the lower surface of the floor panel and the other end portion joined to a lower surface of the floor cross member, and linearly connecting the lower surface of the floor panel and the lower surface of the floor cross member.