Opal Cliffs is an unincorporated community in Santa Cruz County, California, United States.

For statistical purposes, the United States Census Bureau defined Opal Cliffs as a census-designated place (CDP).

As of the census[2] of 2000, there were 6,458 people, 2,843 households, and 1,410 families residing in the CDP.

33.6% of all households were made up of individuals, and 9.4% had someone living alone who was 65 years of age or older.

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