UCLA Mattel Children's Hospital (MCH) at Ronald Reagan UCLA Medical Center is a nationally ranked pediatric acute care children's hospital located in Los Angeles, California. The hospital has 156 pediatric beds, is affiliated with the University of California, Los Angeles David Geffen School of Medicine, and is a member of UCLA Health. The hospital provides comprehensive pediatric specialties and subspecialties to pediatric patients aged 0–21 throughout California. Mattel Children's also sometimes treats adults that require pediatric care. UCLA Mattel Children's Hospital features an ACS verified pediatric level 1 trauma center. The UCLA Mattel Children's Hospital is located on the third and fifth floors of the newly constructed Ronald Reagan UCLA Medical Center.

Ronald Reagan UCLA Medical Center is a hospital located on the campus of the University of California, Los Angeles (UCLA), in Westwood, Los Angeles, California, United States. It is currently ranked by U.S. News & World Report, as the best in California and the West Coast. The hospital provides tertiary care to Los Angeles and the surrounding communities.