A composite shaft includes a shaft body formed from a plurality of polymer impregnated fiber-reinforced material layers having an annular outer surface and an annular inner surface defining a passage. A plurality of internal support members extend along the passage. Each of the plurality of internal support members includes a support body formed from molded plastic having an outer surface that abuts the annular inner surface of the support body, a first end, an opposing second end, and a circular end wall arranged at one of the first end and the opposing second end.