South Pasadena
- County:
- Los Angeles County
- County Seat:
- No
- Area (mi²):
- 3.409
- State:
- California
South Pasadena is a city located in Los Angeles County, California. South Pasadena has a 2026 population of 25,656. South Pasadena is currently declining at a rate of -0.3% annually and its population has decreased by -4.4% since the most recent census, which recorded a population of 26,837 in 2020.