The non-avian theropod dinosaurs are arguably some of the most iconic of extinct animals. One aspect of non-avian theropod biology that has always been of interest is terrestrial locomotion, as well as how it evolved on the line to modern birds. This topic has received extensive research attention over the past 25 years, but key questions remain unanswered. For example, the three-dimensional (3-D) limb posture and limb excursion used during stance and gait, bone loading mechanics or athletic ability in nonavian theropods remains vaguely understood, as does how the locomotor repertoire of modern birds was acquired. In this thesis, the question of theropod locomotion was addressed through a multi-faceted approach that integrated three disparate lines of evidence: fossil theropod footprints and trackways, comparative biomechanics of modern bird and human terrestrial locomotion, and cancellous bone architecture in the main bones of the hindlimb.