Background Erenumab, a fully human monoclonal antibody that targets the calcitonin gene-related peptide receptor, has demonstrated efficacy and safety in the prevention of episodic and chronic migraine. There exists an unmet need to establish the safety of erenumab in older individuals, in view of existing multiple comorbidities, polypharmacy, and age-related physiological changes. This pooled analysis of five large migraine-prevention studies examined the safety of erenumab stratified across age groups, particularly in older populations. Methods Pooled and age-stratified analysis of safety data from the 12-week double-blind treatment phase (DBTP) of five randomized, placebo-controlled Phase 2 and 3 studies of erenumab in participants with episodic or chronic migraine across the age groups < 40 years, 40–49 years, 50–59 years, and ≥ 60 years was completed. The safety of erenumab across age groups was determined by assessing safety endpoints including treatment-emergent adverse events (AEs), serious AEs, and events leading to study drug discontinuation. Results Overall, 3345 participants across five studies were randomized to receive either placebo (n = 1359), erenumab 70 mg (n = 1132) or erenumab 140 mg (n = 854); 3176 (94.9%) completed the DBTP, and 169 (5.1%) discontinued, mainly due to participant decision (110; 3.3%). Overall, 1349 (40.6%), 1122 (33.8%), and 850 (25.6%) participants received at least one dose of placebo, erenumab 70 mg, and erenumab 140 mg, respectively. Incidence of treatment-emergent AEs was similar across all age groups for both doses of erenumab (70 mg or 140 mg) and placebo (< 40 years, 44.0% vs 44.4%; 40–49 years, 42.5% vs 49.2%; 50–59 years, 46.5% vs 41.6%; ≥ 60 years, 43.8% vs 59.4%). Incidence of treatment-emergent serious AEs overall, and stratified by age groups for both doses and placebo was low (< 40 years, 0.9% vs 1.2%; 40–49 years, 1.7% vs 1.9%; and 50–59 years, 1.6% vs 1.1%), with no serious AEs reported in participants aged ≥ 60 years. No deaths were reported. Conclusions Erenumab (70 mg or 140 mg) exhibited a similar safety profile compared with placebo across age groups in individuals with episodic or chronic migraine, with no increased emergence of events due to age. Erenumab was well tolerated in older participants with multiple comorbidities, polypharmacy, and age-related physiological changes. Trial registration number ClinicalTrials.gov Identifiers: NCT02066415, NCT02456740, NCT02483585, NCT03096834, NCT03333109.