Background: Group B Streptococcus (GBS) is a gram-positive, organism that colonizes the gastrointestinal and genitourinary tracts of up to 30% of pregnant women. Although most carriers are asymptomatic, maternal colonization may lead to urinary tract infection, chorioamnionitis and neonatal infection. Early-onset GBS disease remains a major cause of neonatal morbidity worldwide. Objective: To determine the incidence, clinical presentation and disease patterns of earlyonset neonatal GBS disease. Methodology: A cross-sectional analytical study was conducted in the Neonatology units of Sri Jayewardenepura Hospital. All inborn neonates within the first seven days of life with either GBSpositive blood cultures or positive GBS surface swabs and C-reactive protein (CRP) >10 mg/dL were included. Results: The mean age at symptom onset was 2.0 ± 1.1 days. Most affected neonates were term (72.1%) and had normal birth weight (73.0%). Non-specific infection with positive GBS surface swab was the most common presentation, with an incidence of 42.5 per 1,000 live births. The incidences of GBS pneumonia, septicemia, and meningitis were 11.3, 9.9, and 3.8 per 1,000 live births respectively . Early preterm neonates had significantly higher rates of pneumonia (73.3%) and meningitis (26.6%) and more severe clinical manifestations including respiratory distress, cardiovascular instability , metabolic abnormalities and hypothermia. They required greater respiratory and cardiovascular support with increased antibiotics usage. No mortality was reported. Conclusion: Early-onset GBS infection represents a significant neonatal health burden with incidence exceeding global estimates. Maternal screening, intrapartum antibiotic prophylaxis and enhanced neonatal surveillance are essential to reduce morbidity and improve outcomes in Sri Lanka.