The FINA World Championships or World Aquatics Championships are the World Championships for aquatics sports: swimming, diving, high diving, open water swimming, artistic swimming, and water polo. They are run by FINA, and all swimming events are contested in a long course (50-metre) pool.
The event was first held in 1973 in Belgrade, Yugoslavia, and is now held every two years. From 1978 to 1998, the World Championships were held every four years, in the even years between Summer Olympic years. Since 2001, the Championships have been held every two years, in the odd years.