Synchronized swimming is a hybrid of swimming, gymnastics, and dance, consisting of swimmers (either individuals, duets, trios, teams or combos) performing a synchronized routine of elaborate and dramatic moves in the water, accompanied by music.

Synchronized swimming demands first-rate water skills, and requires strength, endurance, flexibility, grace, artistry and precise timing, not to mention exceptional breath control while upside down underwater. Developed in the early 1900s in Canada, it is a sport performed almost exclusively by women, although there is some participation by men. In its early form it was sometimes known as "water ballet".

It is a Summer Olympic Games sport. First demonstrated in 1952, it has been an official event since 1984. Olympic and World Championship competition is not currently open to men, but other international and national competitions allow male competitors. Both USA Synchro and Synchro Canada allow men to compete with women.

Competitors point to the strength, flexibility, and aerobic endurance required to perform difficult routines. Swimmers perform two routines for the judges, one technical and one free.

Synchronized Swimming is governed internationally by FINA (Federation Internationale de Natation Amateur).