Herein, we report the clinical findings, treatment choice, and clinical course of a rare case of Mycoplasma pneumoniae (M. pneumoniae) infection with the sole manifestation of optic neuritis (ON). To the best of our knowledge, this is the first case presenting monosymptomatic visual loss without papillitis, neurological symptoms, and abnormal findings on brain imaging. Related articles about ON after M. pneumoniae infection were reviewed to summarize the clinical presentation, possible mechanisms, clinical survey, treatment, and prognosis of this condition. We propose that a Mycoplasma profile is necessary in children who present with ON, especially when this condition is accompanied by prodromal symptoms of the respiratory tract infection.