Understanding and interpreting non-verbal actions are critical components of social cognition, which are often challenging for autistic individuals. Oxytocin, a neuropeptide known to modulate social behavior and enhance the salience of social stimuli, is being explored as a therapeutic option for improving social mirroring. However, its effects are mediated by context- and person-dependent factors. This study examines the impact of a single intranasal dose of oxytocin (24 IU) on interpersonal motor resonance in young adult men with and without autism. Neurophysiological assessments of corticomotor excitability were performed using transcranial magnetic stimulation while participants observed real-time hand movements displayed by an experimenter demonstrating varying social intent (i.e. showing direct vs averted gaze). While no overall effect of oxytocin on interpersonal motor resonance was observed across groups, person-specific factors significantly influenced outcomes. In the autism group, individuals with higher endogenous oxytocin levels exhibited greater motor resonance during action observation. Autistic individuals with heightened social difficulties or avoidant attachment styles showed enhanced motor resonance following oxytocin administration. These findings highlight the nuanced role of both endogenous and exogenous oxytocin in shaping neurophysiological motor resonance and emphasize the importance of individual variability in assessing oxytocin's therapeutic potential for addressing social challenges in autism.