O'Brien Bay is a bay

Headlands and bays

Headlands and bays are two related features of the coastal environment.- Geology and geography :Headlands and bays are often found on the same coastline. A bay is surrounded by land on three sides, whereas a headland is surrounded by water on three sides. Headlands are characterized by high,...

 lying between Bailey Peninsula and Mitchell Peninsula on the Budd Coast

Budd Coast

Budd Coast , part of Wilkes Land, is that portion of the coast of Antarctica lying between the Hatch Islands, at 109°16'E, and Cape Waldron, at 115°33'E. It was discovered in February 1840 by the U.S. Exploring Expedition under the leadership of Lieutenant Charles Wilkes, and named by Wilkes for...

. First mapped from air photos taken by U.S. Navy Operation Highjump

Operation Highjump

Operation Highjump , officially titled The United States Navy Antarctic Developments Program, 1946-1947, was a United States Navy operation organized by RADM Richard E. Byrd Jr. USN, , Officer in Charge, Task Force 68, and led by RADM Richard H. Cruzen, USN, Commanding Officer, Task Force 68....

 and Operation Windmill

Operation Windmill

Operation Windmill was the United States Navy's Second Antarctica Developments Project, an exploration and training mission to Antarctica in 1947–1948. This operation was a follow up to the First Antarctica Development Project known as Operation Highjump. The expedition was commanded by Commander...

 in 1947 and 1948. Named by the Advisory Committee on Antarctic Names

Advisory Committee on Antarctic Names

The Advisory Committee on Antarctic Names is an advisory committee of the United States Board on Geographic Names responsible for recommending names for features in Antarctica...

 (US-ACAN) for Lieutenant Clement E. O'Brien, United States Navy

United States Navy

The United States Navy is the naval warfare service branch of the United States Armed Forces and one of the seven uniformed services of the United States. The U.S. Navy is the largest in the world; its battle fleet tonnage is greater than that of the next 13 largest navies combined. The U.S...

, communications officer with U.S. Navy Operation Windmill which established astronomical control stations in the Windmill Islands

Windmill Islands

The Windmill Islands are an Antarctic group of rocky islands and rocks about wide, paralleling the coast of Wilkes Land for immediately north of Vanderford Glacier along the east side of Vincennes Bay...

in 1948.