Fact Sheet California’s Population By Hans Johnson, Marisol Cuellar Mejia, Eric McGhee Jan 19, 2024 Growth in the nation’s most populous state has slowed notably in the 21st century, with recent years bringing a drop in population due to higher deaths, lower births, and changes in migration. More than half of Californians under 24 are Latino while more than half of Californians 65 and older are white.