Ernesto is the Spanish, Italian and Portuguese form of Ernest, from the Germanic eornost, meaning "serious" or "earnest", a name that became fashionable in English after Oscar Wilde's The Importance of Being Earnest. Its most famous bearer is the Argentine revolutionary Ernesto "Che" Guevara. Ernesto was number 346 in 2000, peaked at number 324 in 2002 and has slipped to number 878 among boys in 2025.