Optic nerve gliomas (ONG) are benign central nervous system tumours and the most common tumours of the optic nerve in children, often occurring before age 20. These tumours are slow-growing and can be treated with surgery and/or radiation therapy. Surgical resection is, however, associated with significant morbidity and loss of vision in the affected eye. The successful management of ONG requires a multidisciplinary, individualised approach aimed at preserving vision. This case report discusses an 11-year-old Ghanaian male diagnosed with left ONG in July 2023. He presented with blurred vision in the left eye, mild proptosis and poor vision, but no pain, headaches or neurological deficits. A contrast-enhanced magnetic resonance imaging of the orbit showed diffuse fusiform enlargement of the left optic nerve (35 × 12 × 11 mm). The successful management of ONG, in this case, using intensity-modulated radiotherapy demonstrates the potential of advanced radiotherapy techniques in preserving vision and achieving tumour control in pediatric patients, even in resource-limited settings. Continuous follow-up and a multidisciplinary approach are essential for managing the long-term outcomes and ensuring the best possible quality of life for these patients.