The Open Water Swimming competition at the 2009 World Aquatics Championships were held from July 21 to 25 at the beach of Ostia in Rome.
Note: Originally, the Open water events were scheduled to occur on Sunday, July 19 (5K), Tuesday, July 21 (women's 10K) and Thursday, July 23 (women's 25K); however the FINA Bureau on July 18, 2009, altered the open water schedule due to weather conditions in Ostia.