Oddar Meanchey, or Thai: Udon MichaiĀ  is a province (khaet) of Cambodia located in the remote northwest.

It borders the provinces of Banteay Meanchey to the east, Siem Reap to the south and Preah Vihear to the east. Its long northern boundary demarcates part of Cambodia's international border with Thailand. The capital is Samraong town.