The Shackleton Fracture Zone (SFZ) is an undersea fracture zone, mid-oceanic ridge^[1] and fault located in the Drake Passage, at the separation between the Scotia Plate from the Antarctic Plate.^[2] It extends between 59° and 60°40' south latitude and between 56°30' and 61° west longitude and runs in a northwest to southeast direction from the South American continental shelf to the South Shetland Islands. Chile claims the area as part of its Outer Continental Shelf boundary.

The name, recognized by the Advisory Committee on Underwater Features (ACUF) since June 1987, is named after the British polar explorer Ernest Shackleton (1874-1922).

The researchers Juan Ignacio Ipinza Mayor and Cedomir Marangunic Damianovic put forward the scientific theory that the separation of the Pacific and Atlantic Ocean oceans "could be confirmed from the so-called Shackleton Fracture Zone (...) the boundary is then located east of the so-called Cape Horn Meridian".^[3]

• Ernest Shackleton
• Natural delimitation between the Pacific and South Atlantic oceans by the Shackleton Fracture Zone