
Can I apostille a
document in Spanish?

Yes.
The Texas Secretary of State will issue an apostille certificate on any non-recordable document that is in the Spanish language or any other non-English language as long as it’s properly signed and notarized by a Texas notary public.
But the entire notary jurat or acknowledgment text that must be on your non-English document or translated document must be in English; it cannot be in Spanish or any other foreign language. If any of the notary jurat or acknowledgment verbiage is in any language other than English, your document will get rejected by the Texas Secretary of State for notarial error.
If you have a Texas recordable document (birth certificate, death certificate, marriage license, marriage certificate, divorce certificate, divorce decree, TXDPS criminal background check, TXDPS driving records report, etc.) that has been translated into Spanish you must have a English version attached to the Spanish copy and it must be properly signed by a translator and notarized by a Texas notary public.