Juan de Casas y Barrera (born 1740) was a Spanish politician who was the captain general of Venezuela from 1807 to 1809.
He was named successor to Captain General Manuel de Guevara y Vasconcelos [es], who died in 1807 after an illness.
On 14 July 1808, Juan de Casas was confronted first by the French brig Serpent which wanted the captain general to accept Joseph Bonaparte as the king of Spain in place of the deposed Ferdinand VII.
[2] Caracas held a city hall meeting, which ended in a pronunciation of its "fidelity and love to Our King Lord Don Fernando VII" (Spanish: fidelidad y amor al rey Nuestro Señor Don Fernando VII).
The British advised Juan de Casas to form a junta, which he finally ratified, although did not activate, on 29 July.