Ket Sivan (born February 6, 1981) is a Cambodian swimmer, who specialized in sprint freestyle events.
Ket qualified for the women's 50 m freestyle, by receiving a Universality place from FINA in an entry time of 34.68.
She challenged six other swimmers in heat two, including 14-year-olds Sameera Al-Bitar of Bahrain and Christal Clashing of Antigua and Barbuda.
She posted a lifetime best of 34.62 to save a seventh spot over Laos' Vilayphone Vongphachanh by nearly two seconds.
Ket failed to advance into the semifinals, as she placed seventy-first overall out of 75 swimmers on the last day of preliminaries.In early 2013, Ket was named deputy officer under the athletes' commission for the National Olympic Committee of Cambodia.