Rancho Santa Fe is a census-designated place (CDP) in San Diego County, California, United States and a bedroom community of San Diego. The population was 3,252 at the 2000 census. At $245,631, it is one of the highest income communities in the United States with at least 1,000 households. The CDP is primarily all residential with one shopping avenue as well as several private schools, and single family residential areas situated on uncommonly large lots.

Rancho Santa Fe has many strict architectural design codes as can be exemplified by several attempts from local residents to improve upon or build new residences. Forbes reported Rancho Santa Fe as having the third most expensive ZIP code in the United States, and most expensive in California, with a median home sale price of $2,585,000. Some homes in ZIP code 92067 but not within the CDP are valued at more than the median home-value within the Master Planned Community that makes up the official CDP, and many people who live within the 92067 ZIP code cite their community as Rancho Santa Fe even though they do not live within the strict boundaries of the Master Planned Community. The United States Postal Service also calls the entire 92067 and entire 92091 ZIP codes "Rancho Santa Fe".

The downtown is centered around the intersection of Linea del Cielo/Paseo Delicias and La Granada/Via de Santa Fe. It is the site of offices of financial firms, restaurants, and small stores. A library and a school are also located here. The community directory, the Rancho Santa Fe Blue Book, is published annually to provide residents with a comprehensive account of businesses in and around Rancho Santa Fe.