What is California's oldest city?

California's oldest city is San Diego. Founded in 1769, San Diego was the site of the first Spanish mission in California, Mission San Diego de Alcalá. This mission laid the groundwork for the Spanish colonization of California and marked the beginning of the European settlement in what would eventually become the state of California. The city's rich Indigenous history, combined with its role as a critical point in Spanish exploration, makes it a historically significant location. In contrast, Los Angeles, San Francisco, and Sacramento were established later, with San Francisco being founded in 1776, Los Angeles in 1781, and Sacramento developing as a settlement during the Gold Rush in the late 1840s. Thus, the distinction of being the oldest city in California firmly belongs to San Diego.