Your result
Spain — Citizenship by Descent
Not eligible
This is the answer Spanish law gives, and it is not the one most people in your position expect.
Being born in a territory Spain administered is not, in Spanish law, being born in Spain. The Supreme Court has held that Spanish Sahara, Ifni and Spanish Guinea were Spanish territory — subject to Spanish authority — but were never national territory, which is why decolonising them did not alter Spain's borders. It confirmed the same reasoning again in 2020 for people born in the former Spanish Sahara: being born there cannot be equated with being born in Spain.
The practical effect is that birth in one of those territories gives you no claim to Spanish nationality of origin, and does not open the one-year naturalisation route that birth in Spain itself would open. It is a genuinely settled point rather than an argument waiting to be made, and the courts reached it precisely because people did argue the other way.
Two things may still help. First, if a parent or grandparent of yours held Spanish nationality — as a good many people connected to those territories did — then your route is through that person rather than through your own birthplace, and it is worth establishing exactly what documents they held. Second, if you were born in the former Spanish Sahara before September 1977, there is a bill in the Spanish Parliament that would grant nationality to people in precisely that position. It passed the lower house in September 2026 and is with the Senate. It is not law, and we cannot tell you it will become law — but it is live, and it is worth watching.