Embodiments of an orthopedic pillow are provided for supporting the head of a sleeper in a supine position. In one embodiment, the orthopedic pillow includes a base having a centerline, a primary head support surface provided on the base, and laterally-opposed side rails extending upwardly from the base and flanking the primary head support surface. The laterally-opposed side rails include, in turn, interior portions and reinforcement portions. The interior portions are located adjacent the primary head support surface and each formed from a first material having a first stiffness, such as a molded foam having a first density. The reinforcement portions are located outboard of the interior portions, as taken along a lateral axis perpendicular to the centerline. The reinforcement portions formed from a second material having a second stiffness greater than the first stiffness, such as a molded foam having a second density greater than the density.