Background: Preseptal and orbital cellulitis represent a diagnostic continuum in pediatric ophthalmology with significantly different management implications. Rapid, accurate differentiation is essential to prevent vision-threatening complications while avoiding unnecessary imaging and hospitalization. Case Presentation: A previously healthy 12-year-old girl presented with acute onset right eyelid erythema and swelling for two days. Clinical examination revealed marked periorbital edema with tenderness and erythema confined to the eyelid tissues. Critically, visual acuity remained 20/20, extraocular movements were full and painless, no relative afferent pupillary defect was present, and fundoscopic examination was normal. The patient was afebrile with only mild superior visual field restriction secondary to mechanical ptosis from lid swelling. Decision-Making: Based on preserved ocular function and absence of orbital signs, a clinical diagnosis of preseptal cellulitis was established. The decision was made to initiate outpatient oral antibiotic therapy with methicillin-resistant Staphylococcus aureus (MRSA) coverage, deferring computed tomography imaging pending clinical response assessment. Outcome: The patient demonstrated excellent response to oral antibiotics with complete resolution of symptoms within 5 days, confirming the appropriateness of conservative outpatient management. Teaching Points: This case illustrates the critical clinical features distinguishing preseptal from orbital cellulitis, demonstrates evidence-based outpatient management in appropriately selected pediatric patients, and provides a practical algorithmic approach to periorbital infections in children.