Cartí Sugtupu, also spelled Gardi Sugdub, is an island in the San Blas Archipelago in the Guna Yala province of Panama. It is the southernmost and largest of four populated Carti Islands (the others are Cartí Tupile in the north, Carti Yandup in the west, and Carti Muladub in the east), and it lies 1200 meters off the northern coast of mainland Panama. The island is densely populated and houses a small harbour and a museum. Its indigenous inhabitants are Guna.

Cartí Sugtupu can be reached by boat from the nearby onshore settlement of Carti and the Cartí Airport, which are both connected to the main Panamanian road network. The other island groups of San Blas archipelago, including El Porvenir, Cayos Limones, and Cayos Holandeses, can be reached by taxi boat.

The island's population is in the process of relocating to the mainland of Panama due to rising sea levels. As of 2017 this move was on hold until funding for the construction of housing and completion of public amenities was obtained. The move started in June 2024, with 300 families moving to Nuevo Cartí, a new mainland settlement close to the island. Although close by, the new settlement is forested rather than having the same relationship with the sea. Residents described the move with sadness as a major lifestyle change that leaves behind more than 200 years of culture.

The community was considered to be the first in Panama to be displaced by climate change. The government of Panama predicted that the island would be completely underwater by 2050, as well as several other islands in the archipelago.

Delacroix, Matias (7 June 2024). "Image of people moving to new homes in Nuevo Cartí". The Guardian. AP. Retrieved 8 June 2024. Click image for caption.