Drug-induced Sweet syndrome is a rare clinical entity defined by sudden-onset skin lesions with histology showing dense neutrophilic infiltrate without vasculitis associated with the administration of a medication. Reported drug causes of Sweet syndrome span many classes, including immunomodulatory agents, chemotherapeutics, antibiotics, and antihypertensives; however, there are no published cases of opioid-induced Sweet syndrome. This report discusses a case of presumed morphine-induced Sweet syndrome. An 86-year-old female admitted for acute cholecystitis developed a rash five days after admission. Her medications notably included hydralazine, morphine, and acetaminophen. Physical examination revealed periocular edema with scattered vesicles and bullae on the face, neck, and chest, along with erythematous plaques on the right upper extremity. Punch biopsy revealed neutrophilic dermatosis with edema and subepidermal bullae formation, and autoimmune and infectious testing returned negative. While bullous Sweet syndrome caused by hydralazine was initially favored from the results, the rash recurred over a week later without additional doses. Medications were reviewed, and although no additional doses of hydralazine had been administered after it was discontinued, there were two doses of morphine given shortly before the rash reemerged. No additional doses of morphine were administered between the initial eruption and its recurrence. Given the timing in relation to morphine, it was determined to be the cause and was discontinued. The patient was restarted on methylprednisolone for 3 days and experienced remission of the lesions without further recurrence, supporting the diagnosis of morphine-induced Sweet syndrome. This report is the first to discuss this potentially rare adverse drug reaction related to morphine.