A swing arm for a saddle riding vehicle which includes a pivot section connected to a vehicle body, and a wheel support section configured to support a rear wheel and which is capable of swinging around the pivot section, includes a swing arm main body made of a fiber reinforced resin, in which the swing arm main body includes a pivot-side opening configured to open an end on a side of the pivot section, and a rear end opening configured to open an end on a side of the wheel support section, and is formed in a hollow shape continuous from the pivot-side opening to the rear end opening.