The Red Cedar River in northwestern Wisconsin, is a tributary of the Chippewa River, flowing approximately 85 miles from Lake Chetek, a reservoir in southwestern Barron County, through a small chain of lakes, including Birch Lake at Birchwood, Balsam Lake in Washburn County and Red Cedar Lake in far northeastern Barron County to its confluence with the Chippewa, just southeast of Dunnville.
Important tributaries include the Chetek and Hay Rivers.
Important settlements along the river's course include Rice Lake, Cameron, Colfax and Menomonie.
Although the lakes that form the river are located in Sawyer, Washburn and Barron counties, the majority of the river's course is through Dunn County, which it nearly bisects from north to south. In addition to the lakes at the river's source, there are three other important lakes, Rice Lake in Barron County (adjacent to the city of Rice Lake), and two reservoirs in central Dunn County, Tainter Lake and Lake Menomin. Below the dam from Lake Menomin the Red Cedar river is well known for its large walleye population.