John Balleny (died 1857) was the English captain of a whaling schooner, the Eliza Scott, who led an exploration cruise for the English whaling firm Samuel Enderby & Sons to the Antarctic in 1838-1839.
During this expedition, Balleny, sailing in company with Thomas Freeman and the Sabrina, sailed into the Southern Ocean along a corridor of longitude centering on the line of 175°E., south of New Zealand.
The Balleny squadron logged a partial break in the pack ice surrounding the southern continent, discovered the Balleny Islands in 1839, and caught a brief sight of Antarctica itself at 64°58'S., 121°08'E. This patch of icy land is today called the Sabrina Coast.
The Balleny corridor through the Southern Ocean would be used by future explorers such as Robert Falcon Scott, Ernest Shackleton, Roald Amundsen, and Richard E. Byrd, and is used today by surface vessels resupplying McMurdo and other scientific bases located in and around the Ross Sea sector of Antarctica.