Tvarditsa Rocks (Bulgarian: скали Твърдица, Bulgarian: ‘Skali Tvarditsa’ ska-'li tv&r-'di-tsa) is a group of rocks off the north coast of Greenwich Island in the South Shetland Islands, Antarctica situated 1.9 km (1.2 mi) northeast of Ongley Island, 1.3 km (0.81 mi) southwest of Stoker Island and 2.6 km (1.6 mi) west of Sierra Island.

The rocks are named after the town of Tvarditsa in southeastern Bulgaria.

Tvarditsa Rocks are located at 62°24′39″S 59°52′06″W / 62.41083°S 59.86833°W / -62.41083; -59.86833 (Bulgarian mapping in 2009).

• Composite Antarctic Gazetteer
• List of Antarctic islands south of 60° S
• SCAR
• Territorial claims in Antarctica

L.L. Ivanov. Antarctica: Livingston Island and Greenwich, Robert, Snow and Smith Islands. Scale 1:120000 topographic map. Troyan: Manfred Wörner Foundation, 2009. ISBN 978-954-92032-6-4

• Tvarditsa Rocks. SCAR Composite Antarctic Gazetteer
• Bulgarian Antarctic Gazetteer. Antarctic Place-names Commission. (details in Bulgarian, basic data in English)

• Tvarditsa Rocks. Copernix satellite image

This article includes information from the Antarctic Place-names Commission of Bulgaria which is used with permission.