In one aspect, a rotor blade for a wind turbine includes a body extending between a root end and a tip end. The body may include a root portion extending from the root end. The root portion may include an inner surface defining an inner circumference. In addition, the rotor blade may include a root stiffener disposed at least partially within the root portion of the body. The root stiffener may include a plurality of arms extending radially from the inner surface and may be configured to extend circumferentially around only a portion of the inner circumference of the root portion.