As regards island nations, only Cuba. (The DR is not an island since it shares Hispaniola island with Haiti)
As regards the US Commonwealth, only Puerto Rico.
There are also many dozens of Caribbean islands off the shores of mainland Latin American nations where Spanish is the official language. e.g. Margarita Island (VZ), Bay Island (Honduras), San Andres Islands (CO), Cozumel (MX), Corn Island (Nicaragua). Bocas del Toro (Panama).
