A fan shroud and a blower device are provided. The fan shroud includes a shroud wall surface and a plurality of ventilation openings. The shroud wall surface extends around a fan along a radial direction orthogonal to a rotation axis. The plurality of ventilation openings are formed through the shroud wall surface in a thickness direction of the shroud wall surface to allow passing of wind generated by a fan motor. A width of a wall surface side opening on a downstream side of the wind in the ventilation opening is smaller than a width of a lateral wall side opening on an upstream side of the wind in the ventilation opening.