Background: This study aims to assess whether sarcopenia can be used to predict prognosis in patients with heart failure (HF) and if different diagnostic criteria for sarcopenia and diverse regions where studies were conducted could affect prognostic outcomes, thus providing a preliminary basis for early identification and prediction of poor prognosis in HF. Methods: The PubMed, Cochrane, Embase, and CNKI (China National Knowledge Infrastructure) databases were searched from inception until March 2023. Cohort studies evaluating the prognostic effect of sarcopenia in patients with HF were included. Two authors independently assessed the studies according to the Newcastle-Ottawa Scale. The meta-analyses were performed using RevMan 5.3 software. The study results were reported using a checklist of Preferred Reporting Items for Systematic Reviews and Meta-analyses were used to report the study results. Results: A total of 12 studies with 3696 HF patients were included. The results showed that the sarcopenia population had a higher risk of all-cause mortality (HR (hazard ratio) = 1.98, 95% CI (confidence interval): 1.61–2.44) and major adverse cardiovascular events (MACE) (HR = 1.24, 95% CI: 1.06–1.45) compared to the non-sarcopenia population. Moreover, the subgroup analysis reported that different diagnostic criteria for sarcopenia and diverse regions were statistically significant for all-cause mortality, except for the Europe subgroup (HR = 1.34, 95% CI: 0.89–2.02). In the subgroup analysis of MACE, all subgroups were statistically significant except for the European Working Group on Sarcopenia in Older People (EWGSOP) (HR = 1.39, 95% CI: 0.86–2.25) and European subgroups (HR = 1.39, 95% CI: 0.86–2.25). Conclusions: Sarcopenia is associated with poor prognosis, including all-cause mortality and MACE, in patients with HF. However, due to the adoption of various diagnostic criteria in different regions of the world, these results need further validation.