North San Juan is a census-designated place in Nevada County, California, United States, along State Route 49 on the San Juan Ridge in Gold Country. The zip code is 95960. The population was 269 at the 2010 census.
The community's beginnings date back to the California Gold Rush and it prospered during the era of hydraulic mining at nearby Malakoff Diggins State Historic Park from 1850-1884. Beginning in 1867, it was included on the route for the first long-distance telephone line, a historical landmark, between French Corral and French Lake.
In 1880, the population was 675.The original name San Juan was bestowed by a veteran of the Mexican-American War who settled there in 1853 because he thought the site looked like San Juan de Ulúa near Veracruz. When the post office opened in 1857 "North" was added to distinguish it from San Juan in San Benito County.
According to the United States Census Bureau, the CDP covers an area of 2.4 square miles (6.3 km²), all of it land.