Sleep has been shown to be associated with the sympathetic and parasympathetic branches of the autonomic nervous system at rest and during stress. However, sleep has not been examined in the context of sympathovagal balance (the coupled relationship between the sympathetic and parasympathetic nervous systems) during stress. The current study investigated whether sleep quality was associated with sympathovagal activity and reactivity to stress. Female participants (N=59) underwent a psychosocial stress task and completed the Pittsburgh Sleep Quality Index while EKG and ICG data were collected. Sleep quality was associated with pre-ejection period at rest and during stress, ps<.05, but was not associated with high-frequency heart rate variability or with sympathovagal reactivity, ps>.05. These findings suggest that sympathetic activity and reactivity account for a significant amount of variance in the relationship between sleep and the autonomic nervous system.