Purpose: An oxymetazoline 0.1% ophthalmic solution was recently approved for treatment of acquired blepharoptosis in adults. This study's objective was to evaluate the safety profile of oxymetazoline 0.1% when administered once daily for 14-84 days. Patients and Methods: Pooled analysis examined safety outcomes from four randomized, double-masked, placebo-controlled clinical trials conducted at 6, 16, 27, and 35 sites, respectively, in the United States. In total, 568 participants with acquired blepharoptosis were evaluated. Median age was 66 years and 74.8% of participants were female. Overall, 375 participants self-administered oxymetazoline 0.1% to both eyes once/day and 193 self-administered placebo (vehicle) daily. Treatment-emergent adverse event (TEAE) rates, severity, and causality were evaluated in the overall population and within participant subgroups defined based on age, race, and ethnicity. Vital signs and ophthalmic findings were evaluated at predefined study visits. Patient-reported treatment tolerability was recorded at study end. Results: TEAE incidence was similar among participants using oxymetazoline 0.1% (31.2%) or vehicle (30.6%). Nearly all TEAEs were mild-to-moderate, and most were not suspected of being treatment related. Serious TEAEs occurred in four participants receiving oxymetazoline 0.1% and one participant receiving vehicle. Nine and two participants in the oxymetazoline 0.1% and vehicle groups, respectively, discontinued due to a TEAE. Ocular TEAEs occurring in ≥2% of participants receiving oxymetazoline 0.1% were punctate keratitis, conjunctival hyperemia, dry eye, blurred vision, instillation site pain, and corneal vital dye staining, with none occurring in >3.5% of participants. TEAE rates were similar across subgroups based on age, race, and ethnicity. No clinically significant mean changes in vital signs or ophthalmologic findings occurred, and >98% of participants rated oxymetazoline 0.1% as causing no/mild discomfort. Conclusion: Once-daily oxymetazoline 0.1% was safe and well tolerated in participants with acquired blepharoptosis when used for 14-84 days. Safety did not appear to differ based on age, race, or ethnicity.