Speaking on the fringes of a security conference in Doha, where the 2022 World Cup will be held, Jurgen Stock said "a spectrum" of threats, which also included hooliganism, now existed for big sports events.
"It's a spectrum of threats and, unfortunately, these threats are increasing," Stock told reporters.
"It's getting more international and it's getting more complex and that requires more than ever that law enforcement agencies cooperate."
Stock cited recent threats to sports events including hooliganism at the 2016 Euros, cyber-crimes at the Rio Olympics and media reports about the risk of terror attacks at the World Cup next year.
He was a headline speaker at the "Major Event Safety and Security Conference", a two-day event billed as the first of its kind.
Also speaking was Hassan al-Thawadi, Secretary General of the Supreme Committee for Delivery & Legacy, the body overseeing organisation of Qatar's 2022 World Cup.
He told those in the audience that Qatar would host a World Cup that is "robustly safe and secure".