Swimming at the 1999 South Pacific Games took place in Agana, the capital of Guam, at the Southern High School Pool between 30 May and 5 June 1999. It was the eleventh edition of the South Pacific Games. Men's and women's open water events of 5 kilometres were introduced in 1999, with swimmers from American Samoa, Fiji, Guam, New Caledonia, Northern Marianas, Micronesia, Palau, Papua New Guinea, Samoa, and Tahiti competing.