Clark Peninsula is a rocky peninsula, about 3 km (2 mi) long and wide, lying 5 km north-east of Australia's Casey Station at the north side of Newcomb Bay on the Budd Coast of Wilkes Land in Antarctica.
The peninsula was first mapped from aerial photographs taken by the US Navy's Operation Highjump in February 1947 and thought to be an island connected by a steep snow ramp to the continental ice overlying Budd Coast. The term peninsula was considered more appropriate by the Wilkes Station party of 1957 whose headquarters were on this peninsula. It was named by the Advisory Committee on Antarctic Names for Captain John E. Clark, captain of the USS Currituck, seaplane tender and flagship of the western task group of Operation Highjump, Task Force 68, 1946–47.
The 9.4 km2 peninsula is protected under the Antarctic Treaty System as Antarctic Specially Protected Area (ASPA) No.136 because of the long-term and ongoing research programs and monitoring studies carried out on its plant communities and Adélie penguin breeding colonies. Other birds breeding at the site include south polar skuas, Wilson's storm petrels and snow petrels.
Coordinates: 66°15′S 110°33′E / 66.250°S 110.550°E