In 2017-2021, Shasta County, California had a total population of 181,935 - 91,994 (50.6 percent) females and 89,941 (49.4 percent) males. The median age was 41.5 years. An estimated 21.8 percent of the population was under 18 years, 31.8 percent was 18 to 44 years, 26.0 percent was 45 to 64 years, and 20.4 percent was 65 years and older.
An estimated 10.7 percent of the people in Shasta County, California were Hispanic or Latino. An estimated 78.0 percent of the people in Shasta County, California were White alone, non-Hispanic. People of Hispanic origin may be of any race.