Cellulitis is an acute infection of the dermal and subcutaneous layers of the skin, often occurring after a local skin trauma. It is a common diagnosis in both inpatient and outpatient dermatology, as well as in the primary care setting. Cellulitis classically presents with erythema, swelling, warmth, and tenderness over the affected area. There are many other dermatologic diseases, which can present with similar findings, highlighting the need to consider a broad differential diagnosis. Some of the most common mimics of cellulitis include venous stasis dermatitis, contact dermatitis, deep vein thrombosis, and panniculitis. History, local characteristics of the affected area, systemic signs, laboratory tests, and, in some cases, skin biopsy can be helpful in confirming the correct diagnosis. Most patients can be treated as an outpatient with oral antibiotics, with dicloxacillin or cephalexin being the oral therapy of choice when methicillin-resistant Staphylococcus aureus is not a concern.