The scope of this systematic review was to summarize the existing literature on the effects of heart rate variability biofeedback (HRV-BF) on executive functions (EFs) across the lifespan. Specifically, it aimed to investigate the factors that may affect the efficacy of HRV-BF interventions, such as the study population, duration and intensity of the intervention, or the technical equipment. This review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Studies that measured and presented at least one EF were included. We included controlled and uncontrolled trials involving clinical and general populations. From the initial list of 137 papers, 16 final studies were reviewed, with 777 participants. Fifty-six percent of the studies included in this review reported significant positive effects of HRV-BF intervention on at least one EF. Attention was the domain that most often benefited from the intervention. The majority of EF improvements (78%) occurred in studies that addressed patient populations or individuals that may present particular profiles: individuals exposed to stress, professional athletes, war veterans, children and adults with ADHD, and clinical older patients. The remaining studies (22%) that reported significant improvements focused on the general population. Efficacy was neither related to the duration or intensity of the intervention nor related to the technical equipment. Overall, our review shows that HRV-BF may be beneficial (a) to increase attentional skills, inhibition, and working memory and (b) when targeting more vulnerable individuals or individuals with particular profiles. However, further development of standardized, controlled protocols and consistent reporting of effect sizes may contribute to establishing the relevance of HRV-BF biofeedback interventions within the field of cognitive enhancement.