Taking into account titles, both national and overseas, as well as wins, goals scored and conceded, among other factors, said organisation has updated its ranking.
Atletico Nacional were the best team in 2016 after winning the Copa Libertadores, but 2017 La Liga and Champions League winners Real Madrid have clinched the accolade for the fourth time.
Gremio, having claimed the Libertadores in 2017, and Manchester United, who lifted the Europa League, make up the podium for the IFFHS. Here is the top 10 list:
10. Salzburg (Austria)
240,5 points
9. Manchester City (England)
244 points
8. Bayern Munich (Germany)
250 points
7. Juventus (Italy)
254 points
6. Flamengo (Brazil)
256 points
5. PSG (France)
266 points
4. FC Barcelona (Spain)
269 points
3. Manchester United (England)
284 points
2. Gremio (Brazil)
286 points
1. Real Madrid (Spain)
328 points