Day Valley is a census-designated place (CDP) in Santa Cruz County, California, United States.

[2] According to the United States Census Bureau, the CDP has a total area of 18.8 square miles (49 km2), most of which is forest and meadows, with a creek at the crossroads of Valencia Rd.

The 2010 United States Census[4] reported that Day Valley had a population of 3,409.

236 households (18.4%) were made up of individuals, and 93 (7.3%) had someone living alone who was 65 years of age or older.

There were 1,366 housing units at an average density of 72.6 per square mile (28.0/km2), of which 1,007 (78.7%) were owner-occupied, and 273 (21.3%) were occupied by renters.

18.6% of all households were made up of individuals, and 5.8% had someone living alone who was 65 years of age or older.

In the California State Legislature, Day Valley is in the 17th Senate District, represented by Democrat John Laird, and in the 29th Assembly District, represented by Democrat Robert Rivas.

[7] Many early settlers to Day Valley (including some members of the Day and Cox families) are buried in a small cemetery in the Forest and Meadows neighborhood, at the corner of Meadow Road and Downing Drive.