Orthokeratinized odontogenic cysts (OOCs) are relatively uncommon developmental cysts lined with orthokeratinized epithelium consisting of a prominent granular layer and a basal layer of low cuboidal flattened cells that show no tendency for nuclear palisading. These cysts have been considered a distinct entity from odontogenic keratocysts since they exhibit a less aggressive behavior and a very low rate of recurrence. Developmental odontogenic cysts can become infected but serious complications, such as potentially life-threatening cellulitis, are rare. This report describes a rare case of facial cellulitis secondary to an infected OOC located in the mandible of a 27-year-old man. The relevant literature about the clinical-pathological features of OOC is reviewed.