Background Older adults, identified as 65 years and over, a population for which low health literacy is prevalent, represented most people attending primary health care services provided by the Health Service Executive (HSE) in Ireland in 2019. Any limitation in a person’s health literacy, specifically their ability to access, understand and use health information, can affect their ability to make healthcare related decisions. Information on the evidence for health literacy interventions is also required by healthcare providers and policy makers to inform decision-making and service development to improve outcomes for older people. This review aimed to synthesise the evidence on health literacy interventions and health literacy-related outcomes for older adults. The specific objectives were to (1) identify what health literacy interventions exist in relation to older adults’ ability to access, understand, and use health information, (2) determine the health literacy-related outcomes of these interventions, and (3) identify any trends or patterns which may exist between intervention type and outcome. Methods: This review was conducted by following PRISMA guidelines. The electronic databases PubMed, Embase and Scopus were searched for relevant studies concerning health literacy interventions for older persons. Study data were subsequently analysed using a narrative thematic approach in the context of the three key health literacy characteristics; the ability to access, understand and use health information. Results: Thirty-four studies were identified that met the inclusion criteria. The findings show a potential link between individual-focused health literacy interventions and positive health literacy-related outcomes in relation to older persons’ ability to understand and use health information. The review also found that use of health literacy level assessment tools varied with studies either using different tools for the same older adult cohort, or failing to assess pre-intervention health literacy levels altogether. Conclusions: The potential trend found between individual-focused interventions and positive health literacy outcomes suggests that implementing health literacy-related interventions directly to the individual is key. Furthermore, our study found an inconsistency amongst the included studies in relation to the implementation of health literacy assessment tools, with different tools used across most studies, and some studies choosing not to utilise any assessment tool.