Introduction: Drug allergy (DA) complicates clinical management and impacts outcomes. However, data on paediatric DA prevalence and predictors in low-and middle-income countries like Sri-Lanka remain scarce. Objectives: To determine the prevalence and predictors of self-reported DA among children. Methods: Children (6-months to 14-years) were recruited from outpatient-departments at seven tertiary-care hospitals across five provinces. Data were collected via standardized electronic-proforma during one-to-one interviews. Multivariable logistic-regression was used to identify predictors. Results: Among 4,011 children (55.4% male; 73.2% non-atopic), the prevalence of self-reported DA was 2.1% (n=84). Antibiotics were the most frequently implicated (n=37 , 0.9%), followed by nonsteroidal- anti-inflammatory drugs and paracetamol. A family history of DAs was reported in 6.9%. Among the self-reported antibiotic-allergy (AA), most (78%, n=32) reported allergy to betalactams: amoxicillin (n=16), co-amoxiclav (n=4), cephalexin (n=3), and cefotaxime (n=3). Four reported allergies to two antibiotics. Reactions were reported after the first-dose in 70.7%, while 58.6% developed symptoms within two-hours. Commonest manifestations were erythema, pruritus, urticaria and angioedema. Anaphylaxis was reported among eight. Notably , no child had undergone confirmatory testing for AA. Multivariable-analysis showed increasing age tripled the risk of self-reported DA (OR=2.60, 95%CI:1.15-5.88), and a family history of DA doubled the risk (OR=1.94, 95%CI: 1.01- 3.72), while not having atopy appeared protective (OR=0.57 , 95%CI:0.36-0.89). Sex, ethnicity , and chronic illness were not significant. Conclusion: Self-reported AA in Sri-Lanka (0.9%) is lower than in high-income countries (2.5–10%). However, the lack of confirmatory-testing highlights a critical diagnostic gap. Strengthening allergy-specialty services is essential to prevent unnecessary drug restrictions and improve pediatric antimicrobial-stewardship.