Grover Beach, CA has a population of 13,484 and is the 3,103rd largest city in the United States. The population density is 5,831 per sq mi which is 2409% higher than the California average and 6336% higher than the national average. The median age in Grover Beach is 38 which is approximately 5% higher than the California average of 36. In Grover Beach, 48% of the population over 15 years of age are married, 77% speak English and 15% speak Spanish. 65% of Grover Beach residents were born in California, 22% were born out of state, 1% were born outside of the United States and 12% were foreign born.