Millville is a census-designated place (CDP) in Shasta County, California, United States.

[2] According to the United States Census Bureau, the CDP has a total area of 8.2 square miles (21 km2), 97.96% of it land and 2.04% of it water.

44 households (16.4%) were made up of individuals, and 24 (9.0%) had someone living alone who was 65 years of age or older.

There were 287 housing units at an average density of 34.9 per square mile (13.5/km2), of which 230 (85.8%) were owner-occupied, and 38 (14.2%) were occupied by renters.

There were 229 housing units at an average density of 27.7 per square mile (10.7/km2).

12.4% of all households were made up of individuals, and 4.6% had someone living alone who was 65 years of age or older.

In the state legislature Millville is in the 1st Senate District, represented by Republican Megan Dahle,[5] and the 1st Assembly District, represented by Republican Heather Hadwick.

[6] Federally, Millville is in California's 1st congressional district, represented by Republican Doug LaMalfa.