The scent of another person can activate memories, trigger emotions, and spark romantic attraction; however, almost nothing is known about whether and how human scents influence responses to stress. In the current study, 96 women were randomly assigned to smell one of three scents (their romantic partner’s, a stranger’s, or a neutral scent) and exposed to an acute stressor (Trier Social Stress Test). Perceived stress and cortisol were measured continuously throughout the study (5 and 7 times, respectively). Perceived stress was reduced in women who were exposed to their partner’s scent. This reduction was observed during stress anticipation and stress recovery. Cortisol levels were elevated in women who were exposed to a stranger’s scent. This elevation was observed throughout stress anticipation, peak stress, and stress recovery. The current work speaks to the critical role of human olfactory cues in social communication and reveals that social scents can impact both psychological and physiological reactions to stress.