The Santiago Bernabeu club bagged more than a third of the votes from Goal readers, seeing off Manchester United, Barcelona and others
The Santiago Bernabeu side - who won their record 10th Champions League (previously the European Cup) trophy in May - blew away the competition in the poll, picking up 12,441 votes.
Manchester United, whom Louis van Gaal claims are the biggest club in the world, finished runners up with 18.4 per cent of readers supporting the Dutch coach's claim.
Barcelona lagged well their Clasico rivals in our poll but still finished third, with 5,257 votes, while 9.9% claim that Arsenal - despite never having won a Champions League trophy - are unmatched by any other team on the planet size-wise.
Liverpool rounded out the top five a little ahead of Chelsea, AC Milan and Bayern Munich, who were all separated by just 0.1%.
At the bottom of the pile, below 10th-placed Inter (1.2%) and the 'Other' (0.8%) option, were Manchester City (0.6%) and Paris Saint-Germain (0.2%) - proving that having all the money in the world will not force fans to think of you as the biggest club.