Courtois, who has previously stated that his "heart is in Madrid" due to his children living there, has helped the Red Devils reach the knockout rounds at Russia 2018 with maximum points.
Ahead of Belgium's last-16 tie against Japan, Courtois spoke about the prospect of "a nice final" against La Roja, who secured a hat-trick of major international trophies between 2008 and 2012.
"Of course, it's a dream to play a World Cup final, especially to play against Spain because I know a lot of people there. It's a nice final," Courtois told Goal.com.
"I think Spain played good football against Portugal, even though they conceded three goals... I think they play well but they also concede goals."
Spain meet Russia in their round-of-16 tie, while one of Belgium and Japan will face the winner of the match between Brazil and Mexico.