This review aims to identify, appraise, and synthesize research evidence of the association between electronic health (eHealth) literacy and health outcomes in older adults. English-written articles that presented the relationships between eHealth literacy and health-related outcomes in older adults were identified by searching five scientific databases (Web of Science, PubMed, Cochrane Library, APA PsycInfo, and EMBASE) hand-searching reference lists. Searches yielded 2993 studies after duplicates were removed, of which 24 publications were included in the final review. eHealth literacy was relatively low in older adults, and the eHealth Literacy Scale, developed by Norman and Skinner in 2006, was the most frequently used instrument in the included studies (21/24, 87.5%). The health-related outcomes associated with eHealth literacy were grouped into four categories: physical, behavioral, psychosocial, and cognitive. For behavioral (e.g., health-promoting behaviors, self-care, and medication adherence) and cognitive (e.g., health knowledge and health decision making) outcomes, the evidence was mostly consistent that eHealth literacy was positively associated with better outcomes. For physical (e.g., health-related quality of life) and psychosocial outcomes (e.g., anxiety and self-efficacy), the associations were less consistent, with some studies showing significant associations while others showed no associations. Most included studies were assessed as moderate quality. Overall, higher eHealth literacy is associated with more positive health behaviors and better health knowledge and attitude in older adults, however, the associations with some physical and psychosocial outcomes are less consistent. Clarifying the pathways of the relationships between eHealth literacy and some health-related outcomes is needed for further exploring their underlying mechanisms.