A 47-year-old woman presented to the ophthalmology clinic with a 2-week history of eyelid itching and the sensation of a foreign body in the right eye. Examination showed a raised, pigmented area with ill-defined margins protruding from the right upper eyelid (Panel A). Eyelid eversion revealed a large, poorly delineated, pigmented lesion on the right palpebral conjunctiva (Panel B). An excisional biopsy was performed, and pathological analysis showed infiltration of epithelioid and spindle-shaped melanocytes to a depth of 1.8 mm. Immunohistochemical staining was positive for HMB-45, SOX10, and PRAME (preferentially expressed antigen of melanoma). A diagnosis of malignant melanoma of the palpebral conjunctiva, with local invasion of the eyelid, was made. No mutations in BRAF were detected, and no regional lymph-node or distant metastases were observed on evaluation of the cancer stage. Conjunctival melanomas account for a minority of ocular melanomas, most of which arise from the uveal tract. The patient declined surgical excision and underwent treatment with pembrolizumab. At follow-up, which at the time of publication had occurred monthly since the diagnosis was made in August 2021, the lesion had not expanded.