Leicester came from nowhere last season, having narrowly avoided relegation in 2014-2015, to win the title over Mourinho's Chelsea – who started the campaign as champion and only managed a 10th place finish with the Portuguese manager sacked in the process.
Now, Mourinho is preparing to face off with Leicester manager Claudio Ranieri – ironically the last counterpart he faced in the Premier League when he was in charge of Chelsea prior to his departure in December – as United boss in Monday's (AEST) Community Shield and he claims the Italian's triumph could not have happened in Germany's Bundesliga, Spain's LaLiga or Italy's Serie A where the big teams actively weaken their title challengers in the transfer market.
In Germany, Bayern Munich has signed Mats Hummels from Borussia Dortmund, while in Italy, champions Juventus have signed last season's top goalscorer Gonzalo Higuain from Napoli as well as former Roma star Miralem Pjanic.
When asked if Leicester's fairy-tale triumph had changed English football, Mourinho said it might have had a bigger effect on other leagues.
"Maybe English football has changed them. This is the only country where everyone wants this to happen. This is the only country where the football structures allow this to happen," he said.
"In the other countries the powerful clubs don't want this to happen. In the other countries they do not want to have to share the money. They don't want to share TV rights.
"In the other countries they want to be comfortable and know they will always be the top dogs in the Champions League. They want it to be a competition of two, three or four and if possible a competition of just one. So this is a special country.
"You have, around Europe, people who when you listen to them it looks like they are the Mother Teresa of football but they are not. You go to many countries and clearly they are happy the way they are. It is not just about them being powerful. It is also to go to the clubs that can be direct competition and every season steal their best players so they don't want a league.
"In this country we want a league. Everybody wants a league. An amazing story like Leicester brings even more credibility to the Premier League and that's why the Premier League is the Premier League."