Rusokastro Rock (Bulgarian: скала Русокастро, ‘Skala Rusokastro’ ska-'la ru-so-'kas-tro) is a twin rock at the north entrance to McFarlane Strait in the South Shetland Islands, Antarctica extending 170 m (560 ft) in northwest–southeast direction and 70 m (230 ft) wide, with its two parts separated by a 30 m (98 ft) wide passage.

It is situated 1.6 km (0.99 mi) northeast of Pyramid Island, 5.7 km (3.54 mi) northeast of Williams Point on Livingston Island, and 5.7 km (3.54 mi) northwest of Duff Point on Greenwich Island.

The rock is named after the settlement and medieval fortress of Rusokastro in southeastern Bulgaria.

Rusokastro Rock is located at 62°24′18″S 60°05′07″W / 62.40500°S 60.08528°W / -62.40500; -60.08528 (Bulgarian mapping in 2009).

ISBN 978-954-92032-6-4 This article includes information from the Antarctic Place-names Commission of Bulgaria which is used with permission.