Introduction: Sleep plays a fundamental role in cardiovascular autonomic regulation. Heart rate variability (HRV) is a sensitive indicator of this balance and can be negatively influenced by sleep disorders. Objective: To investigate, through a systematic review, the relationship between sleep disorders, HRV and cardiovascular risk. Methods: Systematic review conducted according to PRISMA 2020 in six databases. 42 studies published between 2013 and 2024 that correlated sleep, HRV and cardiovascular outcomes were included. Results: Most studies showed that poor sleep quality and the presence of disorders such as obstructive sleep apnea and chronic insomnia significantly reduce HRV. This reduction was associated with increased blood pressure, risk of arrhythmias and cardiovascular events. Interventions such as the use of CPAP and cognitive-behavioral therapy showed improvement in autonomic parameters. Conclusion: HRV is a reliable marker of the influence of sleep on cardiovascular health. Joint assessment of sleep and HRV can contribute to early risk stratification and the formulation of more effective preventive strategies.