Synchronized swimming (often abbreviated to Synchro) is a hybrid form of swimming, dance and gymnastics, consisting of swimmers (either solos, duets, trios, or teams) performing a synchronized routine of elaborate moves in the water, accompanied by music. Synchronized swimming demands advanced water skills, and requires great strength, endurance, flexibility, grace, artistry and precise timing, as well as exceptional breath control when upside down underwater.

Olympic and World Championship competition is not open to men, but other international and national competitions allow male competitors. Both USA Synchro and Synchro Canada allow men to compete with women. – Most European countries allow men to compete also, France even allows male only podiums, according to the number of participants. In the past decade more men are becoming involved in the sport and a global biannual competition called Men's Cup has been steadily growing.

Competitors show off their strength, flexibility, and aerobic endurance required to perform difficult routines. Swimmers perform two routines for the judges, one technical and one free, as well as age group routines and figures.

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