Redby is a census-designated place (CDP) within the Lower Red Lake unorganized territory in Beltrami County, Minnesota, United States. The population was 957 at the 2000 census.
According to the United States Census Bureau, the CDP has a total area of 12.1 square miles (31.5 km²), of which 11.7 square miles (30.2 km²) are land and 0.5 square mile (1.2 km²) (3.95%) is water.
As of the census of 2000, there were 957 people, 244 households, and 203 families residing in the community. The population density was 82.0 people per square mile (31.7/km²). There were 251 housing units at an average density of 21.5/sq mi (8.3/km²). The racial makeup of the CDP was 1.04% White, 97.81% Native American, 0.21% Asian, and 0.94% from two or more races. Hispanic or Latino of any race were 1.57% of the population.