Bayview-Montalvin is a former census-designated place (CDP) in Contra Costa County, California, United States.

As of the census[2] of 2000, there were 5,004 people, 1,461 households, and 1,164 families living in the CDP.

There were 1,476 housing units at an average density of 2,314.0 per square mile (893.4/km2).

The racial makeup of the CDP was 47.72% White, 11.97% Black or African American, 1.10% Native American, 13.89% Asian, 0.76% Pacific Islander, 19.24% from other races, and 5.32% from two or more races.

16.6% of all households were made up of individuals, and 8.7% had someone living alone who was 65 years of age or older.