William Dunbar (d. September 1881, at sea near Siberia) was employed as ice pilot on the 1879-1881 Jeannette Arctic expedition. After their ship sank in June 1881, Dunbar and his fellow explorers made a long, difficult trek over the ice, finally reaching open water in early September. The crew then divided among three small boats they had lugged across the ice field and then all set sail for the Siberian northern coast. On 12 September a storm engulfed the three boats. One of them, containing expedition second-in-command Charles W. Chipp, William Dunbar and six other men, was separated from the small flotilla. No trace of this boat and crew was ever found, and those on board presumably died at sea or soon thereafter.