Siaya County has six constituencies: Ugenya, Ugunja, Alego Usonga, Gem, Bondo, and Rarieda. Governor James Orengo heads the county.
Below is a list of MPs in Siaya County.
List of MPs in Siaya County
| Constituency | MP | Party |
| Ugenya | David Ouma Ochieng | MDG |
| Ugunja | James Opiyo Wandayi | ODM |
| Alego Usonga | Samuel Onunga Atandi | ODM |
| Gem | Elisha Ochieng Odhiambo | ODM |
| Bondo | Gideon Ochanda Ogolla | ODM |
| Rarieda | Paul Otiende Amollo | ODM |