Background/Objectives: Frailty and sarcopenia are geriatric syndromes associated with increased vulnerability to adverse health outcomes, including functional decline, disability, and mortality. Emerging evidence suggests that oral health interventions may play a role in mitigating these conditions. This systematic review aims to evaluate the impact of oral health interventions on frailty and sarcopenia in older adults. Methods: A systematic search was conducted in PubMed, Scopus, and SciELO databases for studies published up to December 2023. Inclusion criteria comprised experimental and quasi-experimental studies assessing dental interventions and their effects on frailty and sarcopenia in individuals aged 60 years and older. The primary outcomes included frailty index, grip strength, walking speed, and functional dentition. Study quality was assessed using GRADEpro. Results: Eight studies were included. Preventive oral hygiene interventions improved oral health but did not significantly impact frailty scores. Oral exercises significantly improved muscle strength and weight, leading to frailty score reductions (−1.1 points, 95% CI: −1.5 to −0.7, p < 0.01). Swallowing therapies were linked to increased grip strength (+1.8 kg, p = 0.03) and walking speed (+0.2 m/s, p = 0.04), with corresponding frailty index reductions (−0.8 points, 95% CI: −1.2 to −0.4, p = 0.01). The certainty of evidence ranged from very low to moderate. Conclusions: Oral health interventions, particularly oral exercises and swallowing therapies, show potential in reducing frailty and sarcopenia-related outcomes in older adults. However, methodological heterogeneity and low-certainty evidence highlight the need for high-quality, large-scale trials with standardized assessment measures to establish definitive clinical recommendations.