El Cajon
- County:
- San Diego County
- County Seat:
- No
- Area (mi²):
- 14.51
- State:
- California
El Cajon is a city located in San Diego County, California. El Cajon has a 2026 population of 103,291. El Cajon is currently declining at a rate of -0.22% annually and its population has decreased by -2.64% since the most recent census, which recorded a population of 106,087 in 2020.