Hydrodynamic bearing assemblies and apparatuses are disclosed. Such hydrodynamic bearing assemblies may be employed in bearing apparatuses for use in downhole motors of a subterranean drilling system or other mechanical systems. In one embodiment of the present invention, a hydrodynamic bearing assembly includes a plurality of bearing segments distributed circumferentially about an axis. Each bearing segment includes a superhard bearing surface. The plurality of bearing segments define a plurality of seams. Each seam is formed between circumferentially-adjacent bearing segments of the plurality of bearing segments. Further embodiments of the present invention include hydrodynamic bearing apparatuses and downhole motors that may utilize any of the disclosed hydrodynamic bearing assemblies.