BACKGROUND: This systematic review summarizes the benefits of treating blood pressure (BP) in individuals 65 years and older. METHODS: We included randomized trials that evaluated BP-lowering medications or BP targets in individuals 65 years and older. Trials were selected and appraised by pairs of independent reviewers. RESULTS: We included 19 trials (42,134 patients). In individuals 65 years or older, antihypertensive therapy was associated with a reduction in all-cause mortality [relative risk: 0.88 (95% CI: 0.81 to 0.94); high certainty evidence; mean follow-up 31 months], cardiovascular mortality, myocardial infarction, heart failure, stroke, and chronic kidney disease. Individuals 75 years or older had a significant reduction in the risk of all-cause and cardiovascular mortality, stroke, and heart failure. Strict systolic BP targets (<120 mm Hg and <130 mm Hg) were associated with a significant reduction in the risk of all-cause and cardiovascular mortality and heart failure, whereas more liberal systolic targets (<150 mm Hg and <160 mm Hg) were associated with lower risk of heart failure and stroke. Older adults with type 2 diabetes mellitus (DM) had lower risk of chronic kidney disease without a significant reduction in other outcomes. However, there was no significant difference in estimates (i.e., interaction) between those with and without DM. CONCLUSIONS: Individuals aged 65 years and older or 75 years and older who receive antihypertensive therapy have statistically significant reduction in the risk of all-cause and cardiovascular mortality, heart failure, and stroke. There was no statistically significant difference in estimates between those with and without DM.