How to Say "ultimate authority" in Spanish
The Spanish word for “ultimate authority” is “supremo” — C1 level.
English → SpanishC1
nounC1formal
a person or council with the highest power

Examples
La decisión del Supremo es inapelable.
The decision of the Supreme Court is final (cannot be appealed).
El Supremo dictaminó a favor de los ciudadanos.
The Supreme Council ruled in favor of the citizens.
Used with 'El'
When 'supremo' is used as a noun to mean the Supreme Court or the highest council, it is almost always preceded by the masculine article 'el' (El Supremo).
Related Translations
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