The man who has been living in Spain since 1996 had hoped the National Court would overturn earlier decisions made against him.
But his appeal was quashed after he told a residing judge that Spain bordered the countries of "Almeria and Jonquera", a Catalan municipality near the French border.
In its ruling, that court argued that while the Moroccan could express himself "correctly" in Spanish, he couldn't understand the questions asked of him and "lacked basic knowledge about Spain's political reality".
He "didn't know what the Constitution was" or "what elections were for" and didn't know about tax returns or social security, the court added.
This made it impossible to grant Spanish citizenship to the man who is married with two children, judges said in their ruling.
The man, a resident of Catalonia, had previously seen citizenship bids fail in 2009 and 2012, El Público reported.
Under Spanish law, when people apply for citizenship in Spain, they must answer a series of questions demonstrating they have integrated into Spanish society.
The interview takes about ten minutes and involves 30 questions. Applicants are expected to get a score of 27 or above.
In 2013, a Senegalese man was denied citizenship after it emerged he didn't know the name of the wife of Spanish Prime Minister Mariano Rajoy.