| No. of participating countries: 184

| No. of athletes: 2413

The 16th FINA World Championships were held in Kazan, Russia from 24 July to 9 August 2015. Russia hosted this event for the first time. The number of participating national teams (190), athletes (2,400) and the number of medals (75) were the most ever in the history of the championships. This was the first time when the FINA World Championships was linked in to the FINA World Masters Championships that have several athletes (near 5,500), countries (110) and medals (635) which are the most ever too.

Competitions were held in six disciplines again (swimming, open water swimming, diving and high diving, synchronized swimming, and water polo) in three main competition venues. In this edition another historical milestone was passed by premiering the mixed duets in synchronized swimming, letting male synchro swimmers perform for the first time ever at an official FINA event. With the inclusion of the mixed relays in swimming, all five basically individual disciplines have mixed events in their respective programmes.

In Kazan, 31 countries appeared on the overall medal table. The majority of the golds went to China, the United States and Russia. Also, China, the United States and Australia had the most of any medals in total. This was the first time since the 2001 World Aquatics Championships that the United States did not finish in the overall, finishing second to China. In the swimming pool 12 world records were set at these Championships.